Fatigue

Introduction

Fatigue may be defined as a subjective state in which one feels tired or exhausted, and in which the capacity for normal work or activity is reduced. There is, however, no commonly accepted definition of fatigue when it is considered in the context of health and illness. This lack of definition results from the fact that a person's experience of fatigue depends on a variety of factors. These factors include culture; personality; the physical environment (light, noise, vibration); availability of social support through networks of family members and friends; the nature of a particular fatiguing disease or disorder; and the type and duration of work or exercise. For example, the experience of fatigue associated with disease will be different for someone who is clinically depressed, is socially isolated, and is out of shape, as compared to another person who is not depressed, has many friends, and is aerobically fit.

Fatigue is sometimes characterized as normal or abnormal. For example, the feeling of tiredness or even exhaustion after exercising is a normal response and is relieved by resting; many people report that the experience of ordinary tiredness after exercise is pleasant. Moreover, this type of fatigue is called acute since the onset is sudden and the desired activity level returns after resting. On the other hand, there is a kind of fatigue that is not perceived as ordinary; that may develop insidiously over time; is unpleasant or seriously distressing; and is not resolved by rest. This kind of fatigue is abnormal and is called chronic.

Some researchers regard fatigue as a defense mechanism that promotes the effective regulation of energy expenditures. According to this theory, when people feel tired they take steps to avoid further stress (physical or emotional) by resting or by avoiding the stressor. They are then conserving energy. Since chronic fatigue is not normal, however, it is an important symptom of some mental disorders; of a variety of physical diseases with known etiologies (causes); and of medical conditions that have no biological markers although they have recognizable syndromes (patterns of symptoms and signs).

Fatigue is sometimes described as being primary or secondary. Primary fatigue is a symptom of a disease or mental disorder, and may be part of a cluster of such symptoms as pain, fever, or nausea. As the disease or disorder progresses, however, the fatigue may be intensified by the patient's worsening condition, by the other disease symptoms, or by the surgical or medical treatment given to the patient. This subsequent fatigue is called secondary.

Risk factors

Fatigue is a common experience. It is one of the top ten symptoms that people mention when they visit the doctor. Some people, however, are at higher risk for developing fatigue. For example, the risk for women is about 1.5 times the risk for men, and the risk for people who don't exercise is twice that of active people. Some researchers question whether women really are at higher risk, since they are more likely than men to go to the doctor with health problems; also, men are less likely to admit they feel fatigued. Other risk factors include obesity ; smoking; use of alcohol; high stress levels; depression; anxiety; and low blood pressure. Having low blood pressure is usually considered desirable in the United States, but is regarded as a treatable condition in other countries. Low blood pressure or postural hypotension (sudden lowering of blood pressure caused by standing up) may cause fatigue, dizziness, or fainting.

Major sources of chronic fatigue

Disease

There are many diseases and disorders in which fatigue is a major symptom— for example, cancer, cardiovascular disease, emphysema, multiple sclerosis, rheumatic arthritis, systemic lupus erythematosus, HIV/AIDS, infectious mononucleosis, chronic fatigue syndrome, and fibromyalgia. The reasons for the fatigue, however, vary according to the organ system or body function affected by the disease. Physical reasons for fatigue include:

• Circulatory and respiratory impairment. When the patient's breathing and blood circulation are impaired, or when the patient has anemia (low levels of red blood cells), body tissues do not receive as much oxygen and energy. Hence, the patient experiences a general sense of fatigue. Fatigue is also an important warning sign of heart trouble because it precedes 30%–55% of myocardial infarctions (heart attacks) and sudden cardiac deaths.
• Infection. Microorganisms that disturb body metabolism and produce toxic wastes cause disease and lead to fatigue. Fatigue is an early primary symptom of chronic, nonlocalized infections found in such diseases as acquired immune deficiency syndrome (AIDS), Lyme disease, and tuberculosis.
• Nutritional disorders or imbalances. Malnutrition is a disorder that promotes disease. It is caused by insufficient intake of important nutrients, vitamins, and minerals; by problems with absorption of food through the digestive system; or by inadequate calorie consumption. Protein-energy malnutrition (PEM) occurs when people do not consume enough protein or calories; this condition leads to wasting of muscles and commonly occurs in developing countries. In particular, young children who are starving are at risk of PEM, as are people recovering from major illness. In general, malnutrition damages the body's immune function and thereby encourages disease and fatigue. Taking in too many calories for the body's needs, on the other hand, results in obesity, which is a predictor of many diseases related to fatigue.
• Dehydration. Dehydration results from water and sodium imbalances in body tissues. The loss of total body water and sodium may be caused by diarrhea, vomiting, bed rest, exposure to heat, or exercise. Dehydration contributes to muscle weakness and mental confusion; it is a common and overlooked source of fatigue. Once fatigued, people are less likely to consume enough fluids and nutrients, which makes the fatigue and confusion worse.
• Deconditioning. This term refers to generalized organ system deterioration resulting from bed rest and lack of exercise. In the 1950s and 1970s, the National Aeronautics and Space Administration (NASA) studied the effects of bed rest on healthy athletes. The researchers found that deconditioning set in quite rapidly (within 24 hours) and led to depression and weakness. Even mild exercise can counteract deconditioning, however, and has become an important means of minimizing depression and fatigue resulting from disease and hospitalization.
• Pain. When pain is severe enough, it may disrupt sleep and lead to the development of such sleep disorders as insomnia or hypersomnia . Insomnia is the term for having difficulty falling and/or staying asleep. Hypersomnia refers to excessive sleeping. In general, disrupted sleep is not restorative; people wake up feeling tired, and as a result their pain is worsened and they may become depressed. Furthermore, pain may interfere with movement or lead to too much bed rest, which results in deconditioning. Sometimes pain leads to social isolation because the person cannot cope with the physical effort involved in maintaining social relationships, or because family members are unsympathetic or resentful of the ill or injured person's reduced capacity for work or participation in family life. All of these factors worsen pain, contributing to further sleep disruption, fatigue, and depression.
• Stress. When someone experiences ongoing pain and stress, organ systems and functional processes eventually break down. These include cardiovascular, digestive, and respiratory systems, as well as the efficient elimination of body wastes. According to the American Psychiatric Association, various chronic diseases are related to stress, including regional enteritis (intestinal inflammation); ulcerative colitis (a disease of the colon); gastric ulcers; rheumatoid arthritis; cardiac angina, and dysmenorrhea (painful menstruation). These diseases deplete the body's levels of serotonin (a neurotransmitter important in the regulation of sleep and wakefulness, as well as depression), and endorphins (opiate-like substances that moderate pain). Depletion of these body chemicals leads to insomnia and chronic fatigue.
• Sleep disorders. There are a variety of sleep disorders that cause fatigue, including insomnia, hypersomnia, sleep apnea, and restless legs syndrome. For example, hypersomnia may be the result of brain abnormalities caused by viral infections. Researchers studying the aftermath of infectious mononucleosis proposed that exposure to viral infections might change brain function with the effect of minimizing restorative sleep; hence, some people developed hypersomnia. Another common disorder is sleep apnea, in which the patient's breathing stops for at least ten seconds, usually more than 20 times per hour. Snoring is common. People may experience choking and then wake up gasping for air; they may develop daytime hypersomnia (daytime sleepiness) to compensate. Sleep apnea is associated with aging, weight gain, and depression. It is also a risk factor for stroke and myocardial infarctions. Restless legs syndrome is a condition in which very uncomfortable sensations in the patient's legs cause them to move and wake up from sleep, or keep them from falling asleep. All of these disorders reduce the quality of a person's sleep and are associated with fatigue.

Fibromyalgia and chronic fatigue syndrome

Fibromyalgia (also known as myofascial syndrome or fibrositis) is characterized by pain and achiness in muscles, tendons, and ligaments. There are 18 locations on the body where patients typically feel sore. These locations include areas on the lower back and along the spine, neck, and thighs. A diagnostic criterion for fibromyalgia (FM) is that at least 11 of the 18 sites are painful. In addition to pain, people with FM may experience sleep disorders, fatigue, anxiety, and irritable bowel syndrome. Some researchers maintain, however, that when fatigue is severe, chronic, and persistent, FM is indistinguishable from chronic fatigue syndrome (CFS). The care that patients receive for FM or CFS depends in large measure on whether they were referred to a rheumatologist (a doctor who specializes in treating diseases of the joints and muscles), neurologist, or psychiatrist .

Some doctors do not accept CFS (also known as myalgic encephalomyelitis in Great Britain) as a legitimate medical problem. This refusal is stigmatizing and distressing to the person who must cope with disabling pain and fatigue. It is not uncommon for people with CFS to see a number of different physicians before finding one who is willing to diagnose CFS. Nevertheless, major health agencies, such as the Centers for Disease Control (CDC) in the United States, have studied the syndrome. As a result, a revised CDC case definition for CFS was published in 1994 that lists major and minor criteria for diagnosis . The major criteria of CFS include the presence of chronic and persistent fatigue for at least six months; fatigue that does not improve with rest; and fatigue that causes significant interference with the patient's daily activities. Minor criteria include such flu-like symptoms as fever; sore throat; swollen lymph nodes; myalgia (muscle pain); difficulty with a level of physical exercise that the patient had performed easily before the illness; sleep disturbances; and headaches. Additionally, people often have difficulty concentrating and remembering information; they experience extreme frustration and depression as a result of the limitations imposed by CFS. The prognosis for recovery from CFS is poor, although the symptoms are manageable.

Psychological disorders

While fatigue may be caused by many organic diseases and medical conditions, it is a chief complaint for several mental disorders, including generalized anxiety disorder and clinical depression. Moreover, mental disorders may coexist with physical disease. When there is considerable symptom overlap, the differential diagnosis of fatigue is especially difficult.

GENERALIZED ANXIETY DISORDER. People are diagnosed as having generalized anxiety disorder (GAD) if they suffer from overwhelming worry or apprehension that persists, usually daily, for at least six months; and if they also experience some of the following symptoms: unusual tiredness, restlessness and irritability, problems with concentration, muscle tension, and disrupted sleep. Such stressful life events as divorce, unemployment, illness, or being the victim of a violent crime are associated with GAD, as is a history of psychiatric problems. Some evidence suggests that women who have been exposed to danger are at risk of developing GAD; women who suffer loss are at risk of developing depression, and women who experience danger and loss are at risk of developing a mix of both GAD and depression.

While the symptoms of CFS and GAD overlap, the disorders have different primary complaints. Patients with CFS complain primarily of tiredness, whereas people with GAD describe being excessively worried. In general, some researchers believe that anxiety contributes to fatigue by disrupting rest and restorative sleep.

DEPRESSION. In the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSMIV ), the presence of depressed mood or sadness, or loss of pleasure in life, is an important diagnostic criterion for depression. Daily fatigue, lack of energy, insomnia and hypersomnia are indicators of a depressed mood. The symptoms of depression overlap with those of CFS; for example, some researchers report that 89% of people with depression are fatigued, as compared to 86%–100% of people with CFS. The experience of fatigue, however, seems to be more disabling with CFS than with depression. Another difference between CFS and depression concerns the onset of the disorder. Most patients with CFS experience a sudden or acute onset, whereas depression may develop over a period of weeks or months. Also, while both types of patients experience sleep disorders, CFS patients tend to have difficulty falling asleep, whereas depressed patients tend to wake early in the morning.

Some researchers believe that there is a link between depression, fatigue, and exposure to too much REM sleep. There are five distinct phases in human sleep. The first two are characterized by light sleep; the second two by a deep restorative sleep called slow-wave sleep; and the last by rapid eye movement or REM sleep. Most dreams occur during REM sleep. Throughout the night, the intervals of REM sleep increase and usually peak around 8:30 a.m. A sleep deprivation treatment for depression involves reducing the patient's amount of REM sleep by waking him or her around 6:00 A.M. Researchers think that some fatigue associated with disease may be a form of mild depression and that reducing the amount of REM sleep will reduce fatigue by moderating depression.

Managing fatigue

The management of fatigue depends in large measure on its causes and the person's experience of it. For example, if fatigue is acute and normal, the person will recover from feeling tired after exertion by resting. In cases of fatigue associated with influenza or other infectious illnesses, the person will feel energy return as they recover from the illness. When fatigue is chronic and abnormal, however, the doctor will tailor a treatment program to the patient's needs. There are a variety of approaches that include:

• Aerobic exercise. Physical activity increases fitness and counteracts depression.• Hydration (adding water). Water improves muscle turgor or tension and helps to carry electrolytes.
• Improving sleep patterns. The patient's sleep may be more restful when its timing and duration are controlled.
• Pharmacotherapy (treatment with medications). The patient may be given various medications to treat physical diseases or mental disorders; to control pain; or to manage sleeping patterns.
• Psychotherapy. There are several different treatment approaches that help patients manage stress; understand the motives that govern their behavior; or change maladaptive ideas and negative thinking patterns.
• Physical therapy. This form of treatment helps patients improve or manage functional impairments or disabilities.

In addition to seeking professional help, people can understand and manage fatigue by joining appropriate self-help groups ; reading informative books; seeking information from clearinghouses on the Internet; and visiting web sites maintained by national organizations for various diseases.

See also Brain; Breathing-related sleep disorder; Caffeine and related sleep disorders; Circadian rhythm sleep disorder; Pain disorder; Self-help groups; Somatization and somatoform disorders

Resources

BOOKS

Beers, Mark H., and Robert Berkow, eds. The Merck Manual of Diagnosis and Therapy. 17th ed. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

Glaus, A. Fatigue in Patients with Cancer: Analysis and Assessment. Recent Results in Cancer Research, no. 145. Berlin, Germany: Springer-Verlag, 1998.

Hubbard, John R., and Edward A. Workman, eds. Handbook of Stress Medicine: An Organ System Approach. Boca Raton, FL: CRC Press, 1998.

Natelson, Benjamin H. Facing and Fighting Fatigue: A Practical Approach. New Haven, CT: Yale University Press, 1998.

Winningham, Maryl L., and Margaret Barton-Burke, eds. Fatigue in Cancer: A Multidimensional Approach. Sudbury, MA: Jones and Bartlett Publishers, 2000.

PERIODICALS

Natelson, Benjamin H. "Chronic Fatigue Syndrome." JAMA: Journal of the American Medical Association 285, no. 20 (May 23-30 2001): 2557-59.

ORGANIZATIONS

MEDLINEplus Health Information. U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894. (888) 346-3656. <http://www.medlineplus.gov>.

National Chronic Fatigue Syndrome and Fibromyalgia Association. P.O. Box 18426, Kansas City, MO 64133. (816)313-2000. <http://www.4woman.gov/nwhic/references/mdreferrals/ncfsfa.htm>.

Tanja Bekhuis, Ph.D.

Fatigue

Definition

Fatigue may be defined as a subjective state in which one feels tired or exhausted, and in which the capacity for normal work or activity is reduced. There is, however, no commonly accepted definition of fatigue when it is considered in the context of health and illness. This lack of definition results from the fact that a person's experience of fatigue depends on a variety of factors. These factors include culture, personality, the physical environment (light, noise, vibration), availability of social support through networks of family members and friends, the nature of a particular fatiguing disease or disorder, and the type and duration of work or exercise . The experience of fatigue associated with disease will be different for someone who is clinically depressed, is socially isolated, and is out of shape, as compared to another person who is not depressed, has many friends, and is aerobically fit.

Description

Fatigue is sometimes characterized as normal or abnormal. For example, the feeling of tiredness or even exhaustion after exercising is a normal response and is relieved by resting; many people report that the experience of ordinary tiredness after exercise is pleasant. Moreover, this type of fatigue is called "acute" since the onset is sudden and the desired activity level returns after resting. On the other hand, there is fatigue that is not perceived as ordinary, that may develop insidiously over time, is unpleasant or seriously distressing, and is not resolved by rest. This kind of fatigue is abnormal and is called "chronic."

Some researchers regard fatigue as a defense mechanism that promotes the effective regulation of energy expenditures. According to this theory, when people feel tired they take steps to avoid further stress (physical or emotional) by resting or by avoiding the stressor. They are then conserving energy. Since chronic fatigue is not normal, however, it is a common symptom of some mental disorders, a variety of physical diseases with known etiologies (causes), and medical conditions that have no biological markers although they have recognizable syndromes (patterns of symptoms and signs).

Fatigue is sometimes described as being primary or secondary. Primary fatigue is a symptom of a disease or mental disorder, and may be part of a cluster of such symptoms as pain , fever, or nausea. As the disease or disorder progresses, however, the fatigue may be intensified by the patient's worsening condition, by the other disease symptoms, or by the surgical or medical treatment given to the patient. This subsequent fatigue is called secondary.

Risk factors

Fatigue is a common experience. It is one of the top ten symptoms that people mention when they visit the doctor. Some people, however, are at higher risk for developing fatigue. The risk for women is about 1.5 times the risk for men, and the risk for people who do not exercise is twice that of active people. Some researchers question whether women really are at higher risk, since women are more likely than men to go to the doctor with health problems; also, men are less likely to admit they feel fatigued. Other risk factors include obesity, smoking, use of alcohol, high stress levels, depression , anxiety, and low blood pressure. Having low blood pressure is usually considered desirable in the United States, but is regarded as a treatable condition in other countries. Low blood pressure or postural hypotension (sudden lowering of blood pressure caused by standing up) may cause fatigue, dizziness , or fainting .

Major sources of chronic fatigue

Disease

There are many diseases and disorders in which fatigue is a major symptom—for example, cancer, cardiovascular disease, emphysema, multiple sclerosis , rheumatic arthritis, systemic lupus erythematosus, HIV/AIDS, infectious mononucleosis, chronic fatigue syndrome, and fibromyalgia. The reasons for the fatigue, however, vary according to the organ system or body function affected by the disease.

Physical reasons for fatigue include:

• Circulatory and respiratory impairment. When the patient's breathing and blood circulation are impaired, or when the patient has anemia (low levels of red blood cells), body tissues do not receive as much oxygen and energy. Consequently, the patient experiences a general sense of fatigue. Fatigue is also an important warning sign of heart trouble; it precedes 30–55% of myocardial infarctions (heart attacks) and sudden cardiac deaths.
• Infection. Microorganisms that disturb body metabolism and produce toxic wastes cause disease and lead to fatigue. Fatigue is an early primary symptom of chronic, nonlocalized infections found in such diseases as acquired immune deficiency syndrome (AIDS ), Lyme disease , and tuberculosis.
• Nutritional disorders or imbalances. Malnutrition is a disorder that promotes disease. It is caused by insufficient intake of important nutrients, vitamins, and minerals; by problems with absorption of food through the digestive system; or by inadequate calorie consumption. Protein-energy malnutrition (PEM) occurs when people do not consume enough protein or calories; this condition leads to wasting of muscles and commonly occurs in developing countries. In particular, young children who are starving are at risk of PEM, as are people recovering from major illness. In general, malnutrition damages the body's immune function and thereby encourages disease and fatigue. Taking in too many calories for the body's needs, on the other hand, results in obesity, which is a predictor of many diseases related to fatigue.
• Dehydration. Dehydration results from water and sodium imbalances in body tissues. The loss of total body water and sodium may be caused by diarrhea, vomiting, bed rest, overexposure to heat, or exercise. Dehydration contributes to muscle weakness and mental confusion; it is a common and overlooked source of fatigue. Once fatigued, people are less likely to consume enough fluids and nutrients, which makes the fatigue and confusion worse.
• Deconditioning. This term refers to generalized organ system deterioration resulting from bed rest and lack of exercise. In the 1950s and 1970s, the National Aeronautics and Space Administration (NASA) studied the effects of bed rest on healthy athletes. The researchers found that deconditioning occurred rapidly (within 24 hours) and led to depression and weakness. Even mild exercise can counteract deconditioning, however, and it has become an important means of minimizing depression and fatigue resulting from disease and hospitalization.
• Pain. When pain is severe enough, it may disrupt sleep and lead to the development of such sleep disorders as insomnia or hypersomnia . (Insomnia is the term for having difficulty falling and/or staying asleep. Hypersomnia refers to excessive sleeping.) In general, disrupted sleep is not restorative; people wake up feeling tired, and as a result their pain is worsened and they may become depressed. Furthermore, pain may interfere with movement or lead to too much bed rest, which results in deconditioning. Sometimes pain leads to social isolation because the person cannot cope with the physical effort involved in maintaining social relationships, or because family members are unsympathetic or resentful of the ill or injured person's reduced capacity for work or participation in family life. All of these factors worsen pain, contributing to further sleep disruption, fatigue, and depression.
• Stress. When someone experiences ongoing pain and stress, organ systems and functional processes eventually break down. These include cardiovascular, digestive, and respiratory systems, as well as the efficient elimination of body wastes. According to the American Psychiatric Association, various chronic diseases are related to stress, including regional enteritis (intestinal inflammation), ulcerative colitis (a disease of the colon), gastric ulcers, rheumatoid arthritis, cardiac angina, and dysmenorrhea (painful menstruation). These diseases deplete the body's levels of serotonin (a neurotransmitter important in the regulation of sleep and wakefulness, as well as depression), and endorphins (opiate-like substances that moderate pain). Depletion of these body chemicals leads to insomnia and chronic fatigue.
• Sleep disorders. There are a variety of sleep disorders that cause fatigue, including insomnia, hypersomnia, sleep apnea , and restless legs syndrome . For example, hypersomnia may be the result of brain abnormalities caused by viral infections. Researchers studying the aftermath of infectious mononucleosis proposed that exposure to viral infections might change brain function with the effect of minimizing restorative sleep. Another common disorder is sleep apnea, in which the patient's breathing stops for at least 10 seconds, usually more than 20 times per hour. Snoring is common. People may experience choking and then wake up gasping for air; they may develop daytime hypersomnia (daytime sleepiness) to compensate. Sleep apnea is associated with aging, weight gain, and depression. It is also a risk factor for stroke and myocardial infarctions. Restless legs syndrome is a condition in which very uncomfortable sensations in the patient's legs cause them to move and wake up from sleep, or keep them from falling asleep. All of these disorders reduce the quality of a person's sleep and are associated with fatigue.

Fibromyalgia and chronic fatigue syndrome

Fibromyalgia (also known as myofascial syndrome or fibrositis) is characterized by painful and achy muscles, tendons, and ligaments. There are 18 locations on the body where patients typically feel sore. These locations include areas on the lower back and along the spine, neck, and thighs. A diagnostic criterion for fibromyalgia (FM) is that at least 11 of the 18 sites are painful. In addition to pain, people with FM may experience sleep disorders, fatigue, anxiety, and irritable bowel syndrome. Some researchers maintain, however, that when fatigue is severe, chronic, and persistent, FM is indistinguishable from chronic fatigue syndrome (CFS). The care that patients receive for FM or CFS depends in large measure on whether they were referred to a rheumatologist (a doctor who specializes in treating diseases of the joints and muscles), neurologist , or psychiatrist.

Some doctors do not accept CFS (also known as myalgic encephalomyelitis) as a legitimate medical problem. This refusal is stigmatizing and distressing to the person who must cope with disabling pain and fatigue. Many people with CFS may see a number of different physicians before finding one who is willing to diagnose CFS. Nevertheless, major health agencies such as the Centers for Disease Control (CDC) in the United States have studied the syndrome. As a result, a revised CDC case definition for CFS was published in 1994 that lists major and minor criteria for diagnosis. The major criteria of CFS include the presence of chronic and persistent fatigue for at least six months; fatigue that does not improve with rest; and fatigue that causes significant interference with the patient's daily activities. Minor criteria include such flu-like symptoms as fever, sore throat, swollen lymph nodes, myalgia (muscle pain), difficulty with a level of physical exercise that the patient had performed easily before the illness, sleep disturbances, and headaches. Additionally, people often have difficulty concentrating and remembering information and they experience extreme frustration and depression as a result of the limitations imposed by CFS. The prognosis for recovery from CFS is poor, although the symptoms are manageable.

Psychological disorders

While fatigue may be caused by many organic diseases and medical conditions, it is a chief complaint for several mental disorders, including generalized anxiety disorder and clinical depression. Moreover, mental disorders may coexist with physical disease. When there is considerable symptom overlap, the differential diagnosis of fatigue is especially difficult.

GENERALIZED ANXIETY DISORDER

People are diagnosed as having generalized anxiety disorder (GAD) if they suffer from overwhelming worry or apprehension that persists, usually daily, for at least six months, and if they also experience some of the following symptoms: unusual tiredness, restlessness and irritability, problems with concentration, muscle tension, and disrupted sleep. Such stressful life events as divorce, unemployment, illness, or being the victim of a violent crime are associated with GAD, as is a history of psychiatric problems. Some evidence suggests that women who have been exposed to danger are at risk of developing GAD; women who suffer loss are at risk of developing depression, and women who experience danger and loss are at risk of developing a mix of both GAD and depression.

While the symptoms of CFS and GAD overlap, the disorders have different primary complaints. Patients with CFS complain primarily of tiredness, whereas people with GAD describe being excessively worried. In general, some researchers believe that anxiety contributes to fatigue by disrupting rest and restorative sleep.

DEPRESSION

In the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), the presence of depressed mood or sadness, or loss of pleasure in life, is an important diagnostic criterion for depression. Daily fatigue, lack of energy, insomnia, and hypersomnia are indicators of a depressed mood. The symptoms of depression overlap with those of CFS; for example, some researchers report that 89% of people with depression are fatigued, as compared to 86–100% of people with CFS. The experience of fatigue, however, seems to be more disabling with CFS than with depression. Another difference between CFS and depression concerns the onset of the disorder. Most patients with CFS experience a sudden or acute onset, whereas depression may develop over a period of weeks or months. Also, while both types of patients experience sleep disorders, CFS patients tend to have difficulty falling asleep, whereas depressed patients tend to wake early in the morning.

Some researchers believe that there is a link between depression, fatigue, and exposure to too much REM sleep. There are five distinct phases in human sleep. The first two are characterized by light sleep; the second two by a deep restorative sleep called slow-wave sleep; and the last by rapid eye movement, or REM, sleep. Most dreams occur during REM sleep. Throughout the night, the intervals of REM sleep increase and usually peak around 8:30 a.m. A sleep deprivation treatment for depression involves reducing patients' amount of REM sleep by waking them around 6:00 a.m. Researchers think that some fatigue associated with disease may be a form of mild depression and that reducing the amount of REM sleep will reduce fatigue by moderating depression.

Managing fatigue

The management of fatigue depends in large measure on its causes and the person's experience of it. For example, if fatigue is acute and normal, the person will recover from feeling tired after exertion by resting. In cases of fatigue associated with influenza or other infectious illnesses, the person will feel energy return as they recover from the illness. When fatigue is chronic and abnormal, however, the doctor will tailor a treatment program to the patient's needs. There are a variety of approaches that include:

• Aerobic exercise. Physical activity increases fitness and counteracts depression.
• Hydration (adding water). Water improves muscle turgor, or tension, and helps to carry electrolytes.
• Improving sleep patterns. The patient's sleep may be more restful when its timing and duration are controlled.
• Pharmacotherapy (treatment with medications). The patient may be given various medications to treat physical diseases or mental disorders, to control pain, or to manage sleeping patterns.
• Psychotherapy. There are several different treatment approaches that help patients manage stress, understand the motives that govern their behavior, or change maladaptive ideas and negative thinking patterns.
• Physical therapy. This form of treatment helps patients improve or manage functional impairments or disabilities.

In addition to seeking professional help, people can understand and manage fatigue by joining appropriate self-help groups, reading informative books, seeking information from clearinghouses on the Internet, and visiting websites maintained by national organizations for various diseases.

Resources

BOOKS

Beers, Mark H., and Robert Berkow, eds. The Merck Manual of Diagnosis and Therapy, 17th ed. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

Glaus, A. Fatigue in Patients with Cancer: Analysis and Assessment. Recent Results in Cancer Research, no. 145. Berlin, Germany: Springer-Verlag, 1998.

Hubbard, John R., and Edward A. Workman, eds. Handbook of Stress Medicine: An Organ System Approach. Boca Raton, FL: CRC Press, 1998.

Natelson, Benjamin H. Facing and Fighting Fatigue: A Practical Approach. New Haven, CT: Yale University Press, 1998.

Winningham, Maryl L., and Margaret Barton-Burke, eds. Fatigue in Cancer: A Multidimensional Approach. Sudbury, MA: Jones and Bartlett Publishers, 2000.

PERIODICALS

Natelson, Benjamin H. "Chronic Fatigue Syndrome." JAMA: Journal of the American Medical Association 285, no. 20 (May 23–30 2001): 2557–59.

ORGANIZATIONS

MEDLINEplus Health Information. U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894. (888) 346-3656. <http://www.medlineplus.gov>.

National Chronic Fatigue Syndrome and Fibromyalgia Association. P.O. Box 18426, Kansas City, MO 64133. (816) 313-2000.

Tanja Bekhuis, PhD

Rosalyn Carson-Dewitt, MD

Fatigue

Definition

Fatigue is physical and/or mental exhaustion that can be triggered by stress , medication, overwork, or mental and physical illness or disease.

Description

Everyone experiences fatigue occasionally. It is the body's way of signaling its need for rest and sleep. But when fatigue becomes a persistent feeling of tiredness or exhaustion that goes beyond normal sleepiness, it is usually a sign that something more serious is amiss.

Physically, fatigue is characterized by a profound lack of energy, feelings of muscle weakness, and slowed movements or central nervous system reactions. Fatigue can also trigger serious mental exhaustion. Persistent fatigue can cause a lack of mental clarity (or feeling of mental "fuzziness"), difficulty concentrating, and in some cases, memory loss .

Causes & symptoms

Fatigue may be the result of one or more environmental causes such as inadequate rest, improper diet, work and home stressors, or poor physical conditioning, or one symptom of a chronic medical condition or disease process in the body. Heart disease , low blood pressure, diabetes, end-stage renal disease, iron-deficiency anemia, narcolepsy , and cancer can cause long-term, ongoing fatigue symptoms. Acute illnesses such as viral and bacterial infections can also trigger temporary feelings of exhaustion. In addition, mental disorders such as depression can also cause fatigue. A 2002 report suggests that a disorder called hypocalcaemia may be a frequent cause of fatigue.

A number of medications, including antihistamines, antibiotics, and blood pressure medications, may cause drowsiness as a side effect. Individuals already suffering from fatigue who are prescribed one of these medications may wish to check with their healthcare providers about alternative treatments.

Extreme fatigue which persists, unabated, for at least six months, is not the result of a diagnosed disease or illness, and is characterized by flu-like symptoms such as swollen lymph nodes, sore throat , and muscle weakness and/or pain may indicate a diagnosis of chronic fatigue syndrome . Chronic fatigue syndrome (or CFS, sometimes called chronic fatigue immune deficiency syndrome), is a debilitating illness that causes overwhelming exhaustion and a number of neurological and immunological symptoms. Between 1.5 and 2 million Americans are estimated to suffer from the disorder. In late 2001, a panel of experts convened and announced that CFS is definitely associated with the immune system, and likely caused by a virus or bacteria, though no single cause has been identified.

Diagnosis

Because fatigue is a symptom of a number of different disorders, diseases, and lifestyle choices, diagnosis may be difficult. A thorough examination and patient history by a qualified healthcare provider is the first step in determining the cause of the fatigue. A physician can rule out physical conditions and diseases that feature fatigue as a symptom, and can also determine if prescription drugs, poor dietary habits, work environment, or other external stressors could be triggering the exhaustion. Several diagnostic tests may also be required to rule out common physical causes of exhaustion, such as blood tests to check for iron-deficiency anemia.

Diagnosis of chronic fatigue syndrome is significantly more difficult. Because there is no specific biological marker or conclusive blood test to check for the disorder, healthcare providers must rely on the patient's presentation and severity of symptoms to make a diagnosis. In many cases, individuals with chronic fatigue syndrome go through a battery of invasive diagnostic tests and several years of consultation with medical professionals before receiving a correct diagnosis.

Treatment

The treatment of fatigue depends on its direct cause, but there are several commonly prescribed treatments for non-specific fatigue, including dietary and lifestyle changes, the use of essential oils and herbal therapies, deep breathing exercises, traditional Chinese medicine , and color therapy .

Dietary changes

Inadequate or inappropriate nutritional intake can cause fatigue symptoms. To maintain an adequate energy supply and promote overall physical well-being, individuals should eat a balanced diet and observe the following nutritional guidelines:

• Drinking plenty of water. Individuals should try to drink 9 to 12 glasses of water a day. Dehydration can reduce blood volume, which leads to feelings of fatigue.
• Eating iron-rich foods (i.e., liver, raisins, spinach, apricots). Iron enables the blood to transport oxygen throughout the tissues, organs, and muscles, and diminished oxygenation of the blood can result in fatigue.
• Avoiding high-fat meals and snacks. High-fat foods take longer to digest, reducing blood flow to the brain, heart, and rest of the body while blood flow is increased to the stomach.
• Eating unrefined carbohydrates and proteins together for sustained energy.
• Balancing proteins. Limiting protein to 15-20 grams per meal and two snacks of 15 grams is recommended. Not getting enough protein adds to fatigue. Pregnant or breastfeeding women should eat more protein.
• Getting the recommended daily allowance of B complex vitamins (specifically, pantothenic acid, folic acid, thiamine , and vitamin B₁₂ ). Deficiencies in these vitamins can trigger fatigue.
• Getting the recommended daily allowance of selenium, riboflavin , and niacin . These are all essential nutritional elements in metabolizing food energy.
• A 2002 report suggested that calcium and Vitamin D supplementation can lessen fatigue symptoms in person with hypocalcaemia-caused fatigue.
• Controlling portions. Individuals should only eat when they're hungry, and stop when they're full. An over-stuffed stomach can cause short-term fatigue, and individuals who are overweight are much more likely to regularly experience fatigue symptoms.

Lifestyle changes

Lifestyle factors such as a high-stress job, erratic work hours, lack of social or family support, or erratic sleep patterns can all cause prolonged fatigue. If stress is an issue, a number of relaxation therapies and techniques are available to help alleviate tension, including massage, yoga, aromatherapy, hydrotherapy , progressive relaxation exercises, meditation , and guided imagery . Some may also benefit from individual or family counseling or psychotherapy sessions to work through stress-related fatigue that is a result of family or social issues.

Maintaining healthy sleep patterns is critical to proper rest. Having a set "bedtime" helps to keep sleep on schedule. A calm and restful sleeping environment is also important to healthy sleep. Above all, the bedroom should be quiet and comfortable, away from loud noises and with adequate window treatments to keep sunlight and street-lights out. Removing distractions from the bedroom such as televisions and telephones can also be helpful.

Essential oils

Aromatherapists, hydrotherapists, and other holistic healthcare providers may recommend the use of essential oils of rosemary (Rosmarinus officinalis ), eucalyptus blue gum (Eucalyptus globulus ), peppermint ,(Mentha x piperata ), or scots pine oil (Pinus sylvestris ) to stimulate the nervous system and reduce fatigue. These oils can be added to bathwater or massage oil as a topical application. Citrus oils such as lemon, orange, grapefruit, and lime have a similar effect, and can be added to a steam bath or vaporizer for inhalation.

Herbal remedies

Herbal remedies that act as circulatory stimulants can offset the symptoms of fatigue in some individuals. An herbalist may recommend an infusion of ginger (Zingiber officinale ) root or treatment with cayenne (Capsicum annuum ), balmony (Chelone glabra ), damiana (Turnera diffusa ), ginseng (Panax ginseng ), or rosemary (Rosmarinus officinalis ) to treat ongoing fatigue.

An infusion is prepared by mixing the herb with boiling water, steeping it for several minutes, and then removing the herb from the infusion before drinking. A strainer, tea ball, or infuser can be used to immerse loose herb in the boiling water before steeping and separating it. A second method of infusion is to mix the loose herbal preparation with cold water first, bringing the mixture to a boil in a pan or teapot, and then separating the tea from the infusion with a strainer before drinking.

Caffeine-containing central nervous system stimulants such as tea (Camellia senensis ) and cola (Cola nitida ) can provide temporary, short-term relief of fatigue symptoms. However, long-term use of caffeine can cause restlessness, irritability, and other unwanted side effects, and in some cases may actually work to increase fatigue after the stimulating effects of the caffeine wear off. To avoid these problems, caffeine intake should be limited to 300 mg or less a day (the equivalent of 4-8 cups of brewed, hot tea).

Traditional Chinese medicine

Chinese medicine regards fatigue as a blockage or misalignment of qi, or energy flow, inside the human body. The practitioner of Chinese medicine chooses acupuncture and/or herbal therapy to rebalance the entire system. The Chinese formula Minot Bupleurum soup (or Xiao Chia Hu Tang) has been used for nearly 2,000 years for the type of chronic fatigue that comes after the flu. In this condition, the person has low-grade fever, nausea , and fatigue. There are other formulas that are helpful in other cases. Acupuncture involves the placement of a series of thin needles into the skin at targeted locations on the body known as acupoints in order to harmonize the energy flow within the human body.

Deep breathing exercises

Individuals under stress often experience fast, shallow breathing. This type of breathing, known as chest breathing, can lead to shortness of breath, increased muscle tension, inadequate oxygenation of blood, and fatigue. Breathing exercises can both improve respiratory function and relieve stress and fatigue.

Deep breathing exercises are best performed while lying flat on the back on a hard surface, usually the floor. The knees are bent, and the body (particularly the mouth, nose, and face) is relaxed. One hand should be placed on the chest and one on the abdomen to monitor breathing technique. With proper breathing techniques, the abdomen will rise further than the chest. The individual takes a series of long, deep breaths through the nose, attempting to raise the abdomen instead of the chest. Air is exhaled through the relaxed mouth. Deep breathing can be continued for up to 20 minutes. After the exercise is complete, the individual checks again for body tension and relaxation. Once deep breathing techniques have been mastered, an individual can use deep breathing at any time or place as a quick method of relieving tension and preventing fatigue.

Color therapy

Color therapy, also known as chromatherapy, is based on the premise that certain colors are infused with healing energies. The therapy uses the seven colors of the rainbow to promote balance and healing in the mind and body. Red promotes energy, empowerment, and stimulation. Physically, it is thought to improve circulation and stimulate red blood cell production. Red is associated with the seventh chakra, located at the root, or base of the spine. In yoga, the chakras are specific spiritual energy centers of the body.

Therapeutic color can be administered in a number of ways. Practitioners of Ayurvedic, or traditional Indian medicine, wrap their patients in colored cloth chosen for its therapeutic hue. Individuals suffering from fatigue would be wrapped in reds and oranges chosen for their uplifting and energizing properties. Patients may also be bathed in light from a color filtered light source to enhance the healing effects of the treatment.

Individuals may also be treated with color-infused water. This is achieved by placing translucent red colored paper or colored plastic wrap over and around a glass of water and placing the glass in direct sunlight so the water can soak up the healing properties and vibrations of the color. Environmental color sources may also be used to promote feelings of stimulation and energy. Red wall and window treatments, furniture, clothing, and even food may be recommended for their energizing healing properties.

Color therapy can be used in conjunction with both hydrotherapy and aromatherapy to heighten the therapeutic effect. Spas and holistic healthcare providers may recommend red color baths or soaks, which combine the benefits of a warm or hot water soak with energizing essential oils and the fatigue-fighting effects of bright red hues used in color therapy.

Allopathic treatment

Conventional medicine recommends the dietary and lifestyle changes outlined above as a first line of defense against fatigue. Individuals who experience occasional fatigue symptoms may benefit from short-term use of caffeine-containing central nervous stimulants, which make people more alert, less drowsy, and improve coordination. However, these should be prescribed with extreme caution, as overuse of the drug can lead to serious sleep disorders , like insomnia .

Another reason to avoid extended use of caffeine is its associated withdrawal symptoms. People who use large amounts of caffeine over long periods build up a tolerance to it. When that happens, they have to use more and more caffeine to get the same effects. Heavy caffeine use can also lead to dependence. If an individual stops using caffeine abruptly, withdrawal symptoms may occur, including headache , fatigue, drowsiness, yawning, irritability, restlessness, vomiting , or runny nose. These symptoms can go on for as long as a week.

Expected results

Fatigue related to a chronic disease or condition may last indefinitely, but can be alleviated to a degree through some of the treatment options outlined here. Exhaustion that can be linked to environmental stressors is usually easily alleviated when those stressors are dealt with properly.

There is no known cure for chronic fatigue syndrome, but steps can be taken to lessen symptoms and improve quality of life for these individuals while researchers continue to seek a cure.

Prevention

Many of the treatments outlined above are also recommended to prevent the onset of fatigue. Getting adequate rest and maintaining a consistent bedtime schedule are the most effective ways to combat fatigue. A balanced diet and moderate exercise program are also important to maintaining a consistent energy level.

Resources

BOOKS

Davis, Martha et al. The Relaxation & Stress Reduction Workbook. 4th edition. Oakland, CA: New Harbinger Publications, Inc., 1995.

Hoffman, David. The Complete Illustrated Herbal. New York: Barnes & Noble Books, 1999.

Johnson, Hillary. Osler's Web: Inside the Labyrinth of the Chronic Fatigue Syndrome Epidemic. New York: Crown Publishers, 1996.

Lawless, Julia. The Complete Illustrated Guide to Aromatherapy. Boston, MA: Element Books, 1997.

Medical Economics Corporation. The PDR for Herbal Medicines. Montvale, NJ: Medical Economics Corporation, 1998.

PERIODICALS

de Vries, ACH, and Oudesluys-Murphy, AM. "Fatigue Due to Hypocalcaemia." The Lancet (February 2, 2002): 443.

"Immune System Dysfunction May Play a Key Role." Medical Letter on the CDC & FDA (January 20, 2002): 5.

Paula Ford-Martin

Teresa G. Odle

Fatigue

Definition

Fatigue is physical and/or mental exhaustion that can be triggered by stress, medication, overwork, or mental and physical illness or disease.

Description

Everyone experiences fatigue occasionally. It is the body's way of signaling its need for rest and sleep. But when fatigue becomes a persistent feeling of tiredness or exhaustion that goes beyond normal sleepiness, it is usually a sign that something more serious is amiss.

Physically, fatigue is characterized by a profound lack of energy, feelings of muscle weakness, and slowed movements or central nervous system reactions. Fatigue can also trigger serious mental exhaustion. Persistent fatigue can cause a lack of mental clarity (or feeling of mental "fuzziness"), difficulty concentrating, and in some cases, memory loss.

Causes and symptoms

Fatigue may be the result of one or more environmental causes such as inadequate rest, improper diet, work and home stressors, or poor physical conditioning, or one symptom of a chronic medical condition or disease process in the body. Heart disease, low blood pressure, diabetes, end-stage renal disease, iron-deficiency anemia, narcolepsy, and cancer can cause long-term, ongoing fatigue symptoms. Acute illnesses such as viral and bacterial infections can also trigger temporary feelings of exhaustion. In addition, mental disorders such as depression can also cause fatigue.

A number of medications, including antihistamines, antibiotics, and blood pressure medications, may cause drowsiness as a side-effect. Individuals already suffering from fatigue who are prescribed one of these medications may wish to check with their healthcare provider about alternative treatments.

Extreme fatigue which persists, unabated, for at least six months, is not the result of a diagnosed disease or illness, and is characterized by flu-like symptoms such as swollen lymph nodes, sore throat, and muscle weakness and/or pain may indicate a diagnosis of chronic fatigue syndrome. Chronic fatigue syndrome (sometimes called chronic fatigue immune deficiency syndrome), is a debilitating illness that causes overwhelming exhaustion and a constellation of neurological and immunological symptoms. Between 1.5 and 2 million Americans are estimated to suffer from the disorder.

Diagnosis

Because fatigue is a symptom of a number of different disorders, diseases, and lifestyle choices, diagnosis may be difficult. A thorough examination and patient history by a qualified healthcare provider is the first step in determining the cause of the fatigue. A physician can rule out physical conditions and diseases that feature fatigue as a symptom, and can also determine if prescription drugs, poor dietary habits, work environment, or other external stressors could be triggering the exhaustion. Several diagnostic tests may also be required to rule out common physical causes of exhaustion, such as blood tests to check for iron-deficiency anemia.

Diagnosis of chronic fatigue syndrome is significantly more difficult. Because there is no specific biological marker or conclusive blood test to check for the disorder, healthcare providers must rely on the patient's presentation and severity of symptoms to make a diagnosis. In many cases, individuals with chronic fatigue syndrome go through a battery of invasive diagnostic tests and several years of consultation with medical professionals before receiving a correct diagnosis.

Treatment

Conventional medicine recommends the dietary and lifestyle changes outlined above as a first line of defense against fatigue. Individuals who experience occasional fatigue symptoms may benefit from short term use of caffeine-containing central nervous stimulants, which make people more alert, less drowsy, and improve coordination. However, these should be prescribed with extreme caution, as overuse of the drug can lead to serious sleep disorders, like insomnia.

Another reason to avoid extended use of caffeine is its associated withdrawal symptoms. People who use large amounts of caffeine over long periods build up a tolerance to it. When that happens, they have to use more and more caffeine to get the same effects. Heavy caffeine use can also lead to dependence. If an individual stops using caffeine abruptly, withdrawal symptoms may occur, including headache, fatigue, drowsiness, yawning, irritability, restlessness, vomiting, or runny nose. These symptoms can go on for as long as a week.

Alternative treatment

The treatment of fatigue depends on its direct cause, but there are several commonly prescribed treatments for non-specific fatigue, including dietary and lifestyle changes, the use of essential oils and herbal therapies, deep breathing exercises, traditional Chinese medicine, and color therapy.

Dietary changes

Inadequate or inappropriate nutritional intake can cause fatigue symptoms. To maintain an adequate energy supply and promote overall physical well-being, individuals should eat a balanced diet and observe the following nutritional guidelines:

• Drinking plenty of water. Individuals should try to drink 9 to 12 glasses of water a day. Dehydration can reduce blood volume, which leads to feelings of fatigue.
• Eating iron-rich foods (i.e., liver, raisins, spinach, apricots). Iron enables the blood to transport oxygen throughout the tissues, organs, and muscles, and diminished oxygenation of the blood can result in fatigue.
• Avoiding high-fat meals and snacks. High fat foods take longer to digest, reducing blood flow to the brain, heart, and rest of the body while blood flow is increased to the stomach.
• Eating unrefined carbohydrates and proteins together for sustained energy.
• Balancing proteins. Limiting protein to 15-20 grams per meal and two snacks of 15 grams is recommended, but not getting enough protein adds to fatigue. Pregnant or breastfeeding women should get more protein.
• Getting the recommended daily allowance of B complex vitamins (specifically, pantothenic acid, folic acid, thiamine, and vitamin B₁₂). Deficiencies in these vitamins can trigger fatigue.
• Getting the recommended daily allowance of selenium, riboflavin, and niacin. These are all essential nutritional elements in metabolizing food energy.
• Controlling portions. Individuals should only eat when they're hungry, and stop when they're full. An overstuffed stomach can cause short-term fatigue, and individuals who are overweight are much more likely to regularly experience fatigue symptoms.

Lifestyle changes

Lifestyle factors such as a high-stress job, erratic work hours, lack of social or family support, or erratic sleep patterns can all cause prolonged fatigue. If stress is an issue, a number of relaxation therapies and techniques are available to help alleviate tension, including massage, yoga, aromatherapy, hydrotherapy, progressive relaxation exercises, meditation, and guided imagery. Some individuals may also benefit from individual or family counseling or psychotherapy sessions to work through stress-related fatigue that is a result of family or social issues.

Maintaining healthy sleep patterns is critical to proper rest. Having a set "bedtime" helps to keep sleep on schedule. A calm and restful sleeping environment is also important to healthy sleep. Above all, the bedroom should be quiet and comfortable, away from loud noises and with adequate window treatments to keep sunlight and streetlights out. Removing distractions from the bedroom such as televisions and telephones can also be helpful.

Essential oils

Aromatherapists, hydrotherapists, and other holistic healthcare providers may recommend the use of essential oils of rosemary (Rosmarinus officinalis ), eucalyptus blue gum (Eucalyptus globulus ), peppermint, (Mentha x piperata ), or scots pine oil (Pinus sylvestris ) to stimulate the nervous system and reduce fatigue. These oils can be added to bathwater or massage oil as a topical application. Citrus oils such as lemon, orange, grapefruit, and lime have a similar effect, and can be added to a steam bath or vaporizer for inhalation.

Herbal remedies

Herbal remedies that act as circulatory stimulants can offset the symptoms of fatigue in some individuals. An herbalist may recommend an infusion of ginger (Zingiber officinale ) root or treatment with cayenne (Capsicum annuum ), balmony (Chelone glabra ), damiana (Turnera diffusa ), ginseng (Panax ginseng ), or rosemary (Rosmarinus officinalis ) to treat ongoing fatigue.

An infusion is prepared by mixing the herb with boiling water, steeping it for several minutes, and then removing the herb from the infusion before drinking. A strainer, tea ball, or infuser can be used to immerse loose herb in the boiling water before steeping and separating it. A second method of infusion is to mix the loose herbal preparation with cold water first, bringing the mixture to a boil in a pan or teapot, and then separating the tea from the infusion with a strainer before drinking.

Caffeine-containing central nervous system stimulants such as tea (Camellia senensis ) and cola (Cola nitida ) can provide temporary, short-term relief of fatigue symptoms. However, long-term use of caffeine can cause restlessness, irritability, and other unwanted side effects, and in some cases may actually work to increase fatigue after the stimulating effects of the caffeine wear off. To avoid these problems, caffeine intake should be limited to 300 mg or less a day (the equivalent of 4-8 cups of brewed, hot tea).

Traditional Chinese medicine

Chinese medicine regards fatigue as a blockage or misalignment of qi, or energy flow, inside the human body. The practitioner of Chinese medicine chooses acupuncture and/or herbal therapy to rebalance the entire system. The Chinese formula Minot Bupleurum soup (or Xiao Chia Hu Tang) has been used for nearly 2,000 years for the type of chronic fatigue that comes after the flu. In this condition, the person has low-grade fever, nausea, and fatigue. There are other formulas that are helpful in other cases. Acupuncture involves the placement of a series of thin needles into the skin at targeted locations on the body known as acupoints in order to harmonize the energy flow within the human body.

Deep breathing exercises

Individuals under stress often experience fast, shallow breathing. This type of breathing, known as chest breathing, can lead to shortness of breath, increased muscle tension, inadequate oxygenation of blood, and fatigue. Breathing exercises can both improve respiratory function and relieve stress and fatigue.

Deep breathing exercises are best performed while laying flat on the back on a hard surface, usually the floor. The knees are bent, and the body (particularly the mouth, nose, and face) is relaxed. One hand should be placed on the chest and one on the abdomen to monitor breathing technique. With proper breathing techniques, the abdomen will rise further than the chest. The individual takes a series of long, deep breaths through the nose, attempting to raise the abdomen instead of the chest. Air is exhaled through the relaxed mouth. Deep breathing can be continued for up to 20 minutes. After the exercise is complete, the individual checks again for body tension and relaxation. Once deep breathing techniques have been mastered, an individual can use deep breathing at any time or place as a quick method of relieving tension and preventing fatigue.

Color therapy

Color therapy, also known as chromatherapy, is based on the premise that certain colors are infused with healing energies. The therapy uses the seven colors of the rainbow to promote balance and healing in the mind and body. Red promotes energy, empowerment, and stimulation. Physically, it is thought to improve circulation and stimulate red blood cell production. Red is associated with the seventh chakra, located at the root; or base of spine. In yoga, the chakras are specific spiritual energy centers of the body.

Therapeutic color can be administered in a number of ways. Practitioners of Ayurvedic, or traditional Indian medicine, wrap their patients in colored cloth chosen for its therapeutic hue. Individuals suffering from fatigue would be wrapped in reds and oranges chosen for their uplifting and energizing properties. Patients may also be bathed in light from a color filtered light source to enhance the healing effects of the treatment.

Individuals may also be treated with color-infused water. This is achieved by placing translucent red colored paper or colored plastic wrap over and around a glass of water and placing the glass in direct sunlight so the water can soak up the healing properties and vibrations of the color. Environmental color sources may also be used to promote feelings of stimulation and energy. Red wall and window treatments, furniture, clothing, and even food may be recommended for their energizing healing properties.

Color therapy can be used in conjunction with both hydrotherapy and aromatherapy to heighten the therapeutic effect. Spas and holistic healthcare providers may recommend red color baths or soaks, which combine the benefits of a warm or hot water soak with energizing essential oils and the fatigue-fighting effects of bright red hues used in color therapy.

Prognosis

Fatigue related to a chronic disease or condition may last indefinitely, but can be alleviated to a degree through some of the treatment options outlined here. Exhaustion that can be linked to environmental stressors is usually easily alleviated when those stressors are dealt with properly.

There is no known cure for chronic fatigue syndrome, but steps can be taken to lessen symptoms and improve quality of life for these individuals while researchers continue to seek a cure.

Prevention

Many of the treatments outlined above are also recommended to prevent the onset of fatigue. Getting adequate rest and maintaining a consistent bedtime schedule are the most effective ways to combat fatigue. A balanced diet and moderate exercise program are also important to maintaining a consistent energy level.

Resources

BOOKS

Davis, Martha, et al. The Relaxation & Stress Reduction Workbook. 4th ed. Oakland, CA: New Harbinger Publications, Inc., 1995.

Hoffman, David. The Complete Illustrated Herbal. New York: Barnes & Noble Books, 1999.

KEY TERMS

Aromatherapy— The therapeutic use of plantderived, aromatic essential oils to promote physical and psychological well-being.

Guided imagery— The use of relaxation and mental visualization to improve mood and/or physical well-being.

Hydrotherapy— Hydrotherapy, or water therapy, is use of water (hot, cold, steam, or ice) to relieve discomfort and promote physical well-being.

Fatigue

BIBLIOGRAPHY

Fatigue is an experienced state of discomfort, aversion, and inability to perform, otherwise known as tiredness or weariness (Bartley 1943; Bartley & Chute 1947). The term applies to the total individual (the organism-as-a-person) and not properly to an organ or tissue. Fatigue is to be distinguished from impairment, which refers to the inability of cells or tissues to perform. Fatigue is sometimes confused with work decrement, for quite often the inquirer is actually interested in work output rather than in the state of the performer.

Fatigue is brought about in various ways, one common cause being discomfort in muscles induced by exertion, another being impairment. Very often, however, fatigue arises from some sort of disorganization within the individual. This is induced, in part, through confrontation with circumstances that are disliked or considered futile and useless. The disorganization referred to here can be described at various body-process levels. Disorganization can involve a disruption in the proper timing of various processes or a conflict between these processes with subsequent tension, awkwardness, and forgetfulness that result in discomfort and the realization of inadequacy.

Chronic fatigue often represents an unwholesome outlook on daily routine or life in general or arises from personality disorganization rather than some debilitating body processes at a lower level (Muncie 1941).

Critique of common conceptions . The common outlook that confuses fatigue with impairment is characterized by several points, some of which are acceptable and some not (Bartley 1951). First is the view that activity modifies the acting system, and that the modification is a chemical one. Fatigue is taken to be such a modification. However, this is really impairment and is a phenomenon that takes place at the tissue level, whereas fatigue is a phenomenon at the personality level–the experience, the self-awareness of condition. It is also assumed that fatigue can be either a general body condition or specifically localized. The slowing down of a process is taken to be the evidence of fatigue or, by some writers, to be fatigue itself. Here again, it seems to be impairment that is at issue.

Conventional assumptions shift from considering fatigue as tissue effects to considering it as the way the organism-as-a-person behaves. Even at this level compensation is generally overlooked in human performance. This is evidenced in the tacit assumption made by many that the subject has only one way of performing a given task. For example, it is not presumed that one muscle fiber group may be recovering while some other group is taking its place in carrying on over-all performance. But this type of compensation does occur, and it makes many of the simple, customarily performed “fatigue” experiments inappropriate and inadequate.

It is also false to assume that fatigue developed in one kind of performance may be measured by using an altogether different performance as a test.

The concern with fatigue as distinct from work output arises most directly and forcefully in medical practice and is even encountered in athletics. Physicians are being constantly confronted with patients who complain of tiredness, sometimes in connection with convalescence from debilitating disease or simply as a syndrome of its own (Alvarez 1941; Harms & Soniat 1952; Muncie 1941). On the other hand, work output is generally the main concern in industry (Dill et al. 1936; Edwards et al. 1935). Fatigue is often a term incorrectly inferred when an individual notices certain symptoms. In this case, what is called fatigue is self-diagnosis rather than something that arises as a directly felt inability to perform. Thus, a patient may tell an ophthalmologist that he has visual fatigue, inferring this (a self-diagnosis) from the fact that after reading awhile what he sees becomes blurred. This is different than his reporting how he feels. Such a usage of fatigue is to be avoided if the language on fatigue is to be consistent.

Finally, according to the conventional view, there are several kinds of fatigue. The more basic categorization distinguishes objective fatigue (work decrement); subjective fatigue (the experience of tiredness); and physiological fatigue (change or reduction in a specific body process).

Although there are various additionally specified kinds of fatigue, when fatigue exists it is essentially the same in all cases. The core of fatigue is the self-realization of relative inability to carry on. It is a negative orientation toward a task demand. Although the stance toward demand is always essentially the same, various fringe details (various sensory and other components) may vary from case to case, but they are mere details in the unique over-all syndrome that is distinguishable as fatigue.

For example, fatigue arising in intellectual tasks should not be called mental fatigue, if by that one means a special kind of fatigue. Mental fatigue is only the fatigue that arises in intellectual (mental) tasks. Despite the fact that many kinds of tasks may lead to fatigue, no implication that there are many kinds of fatigue should be made.

So many loosely related phenomena have been called fatigue that it has been suggested that the word be done away with entirely (Muscio 1921). Bartley and colleagues (Bartley 1943; 1951; 1957; Bartley & Chute 1945; 1947) have chosen rather to retain the word in its original meaning (i.e., for the phenomena first labeled “tiredness”) and rename other phenomena associated with it.

Problems in studying fatigue . Many studies that are meant to be studies of fatigue begin with questions about the experience of tiredness and inability to continue performance and end up by bypassing these questions and by providing information about other problems. For example, an investigator may note that workers in a plant feel sluggish and ineffective during mid-morning and mid-afternoon. He may suppose that this has something to do with blood sugar level. In his study he finds that at these times blood sugar level is lowest. He may then try a plan whereby the workers take in the same total amount of food per day but eat varying numbers of meals. Some eat two, some three, some four, and some even five meals per day. Blood sugar level is then tested periodically throughout the day. It is found that where many meals are eaten the blood sugar level never falls as low at any part of the work day as it does when few meals are eaten. At this point, the investigator assumes his study is completed. He should continue and determine whether the feeling of sluggishness is eliminated or greatly reduced by redistributing food intake into a greater number of meals, with the total intake held constant. It is only when he has performed this additional step that the original questions of sluggishness and inefficiency receive an answer. It is only then that the investigation becomes a fatigue investigation.

One of the persistent problems in dealing with fatigue is its measurement. It is always expected that if an entity exists it can be measured. The definition of fatigue as a relation to demand in which the individual feels his own inability to go on makes easy measurement unattainable. When work output is all that is to be measured, such measurement is easily made. However, the problem of measuring fatigue as defined here is no different from the problem of measuring anxiety, depression, boredom, hope, anger, or a virtually uncountable number of other states of the organ-ism-as-a-person. Thus, the concept of fatigue should not be singled out for criticism because it refers to a phenomenon difficult to quantify. Nevertheless, such criticism has been leveled, at times, against what is conventionally called “subjective fatigue,” for that reason.

The first point to be recognized is that the phenomenon in question must exist in order to be measured or dealt with in any way. The first step in studying it is to produce it. The second is to manipulate conditions under which it occurs. The next point to realize is that the person fatigued is the only one able to state when it exists. The observations made by all others have to do with overt performance, body process, or both, which are not fatigue although they may be closely related to it in some way. It is also to be recognized that the problem of quantitatively dealing with fatigue involves either developing a fatigue scale or choosing a fatigue point, such as the point at which the performer is no longer able to continue.

It will become quickly evident that in most cases the crucial conditions that lead to fatigue lie within the subject himself rather than the external conditions that produce the demand. Whatever is done to study fatigue, the organism-centered approach is necessary. In fact, it is necessary in trying to understand work output as well.

In certain ways, the phenomena that are per-sonalistic rather than environmental can be studied more concretely than might be supposed. For example, it certainly is possible to manipulate goals (which are personalistic phenomena). In setting a task for a subject one can tell him something that will indicate the amount of time required to perform the task. One can then vary the amount of time so indicated to see what remoteness of goals has to do with the self-assessments of the subjects at various moments during performance and whether this variable has anything to do with the point at which “exhaustion” is reached. Other such dimensions and their body-process concomitants can also be chosen.

Another problem in studying fatigue has to do with how far various subjects will push themselves either in their use of energy resources or in experiencing bodily discomfort. This problem is related to motivation, and its solution may actually be a way of dealing with or measuring motivation. This problem is encountered not only in psychological experimentation but also in the physiological treadmill experiments. Some subjects “reach their limits” in muscular exertion before oxygen debt occurs, while others do not. No physiologist would expect that a subject would be exhausted before oxygen debt appears. These results illustrate the difference in the amount that individuals will push themselves. Thus the problem of subjectivity is as inherent in many phases of physiology as in psychology. Hence it cannot be disposed of by assuming that it occurs only in nonbehavioristic types of research.

Relieving fatigue. Various drugs and other substances have been tried by investigators to relieve fatigue and improve performance in athletic activities (Karpovich 1959; Smith & Beecher 1959).

Fatigue may often be relieved by inducing a change of attitude or attention or by shifting from one task to another rather than by rest (inactivity). Supposedly the needed change involves reorganization within the individual rather than a replenishment of energy.

Fatigue and the syndrome called stress by Selye (1956) have a lot in common, particularly certain factors of origin. Selye’s discoveries and concepts go a long way toward providing a bodily basis for human incapacity, and when this is coupled with a monistic psychology, which attempts to understand human behavior, considerable progress seems to be possible.

S. Howard Hartley

[Other relevant material may be found inACHIEVEMENT MOTIVATION; INFANCY, article OnTHE EFFECTS OF EARLY EXPERIENCE; SLEEP; STRESS.]

BIBLIOGRAPHY

ALVAREZ, W. C. 1941 What Is the Matter With the Patient Who Is Chronically Tired? Journal of the Missouri State Medical Association38 : 365–368.

HARTLEY, S. HOWARD 1943 Conflict, Frustration and Fatigue. Psychosomatic Medicine5 : 160–163.

BARTLEY, S. HOWARD 1951 Fatigue and Efficiency. Pages 318-347 in Harry Helson (editor), Theoretical Foundations of Psychology. New York: Van Nostrand.

HARTLEY, S. HOWARD 1957 Fatigue and Inadequacy. Physiological Reviews37 : 301–324.

HARTLEY, S. HOWARD; and CHUTE, ELOISE 1945 A Preliminary Clarification of the Concept of Fatigue. Psy-chological Review52 : 169–174.

HARTLEY, S. HOWARD; and CHUTE, ELOISE 1947 Fatigue and Impairment in Man. New York: McGraw-Hill.

DILL, D. B. et al. 1936 Industrial Fatigue. Journal of Industrial Hygiene and Toxicology18 : 417–431.

EDWARDS, H. T.; THORNDIKE, A.; and DILL, D. B. 1935 The Energy Requirement in Strenuous Muscular Exercise. New England Journal of Medicine213 : 532–535.

HARMS, H. E.; and SONIAT, T. L. L. 1952 The Meaning of Fatigue. Medical Clinics of North America36 : 311–317.

KARPOVICH, P. V. 1959 Effect of Amphetamine Sulfate on Athletic Performance. Journal of the American Medical Association170 : 558–561.

Muncie, Wendell 1941 Chronic Fatigue. Psychosomatic Medicine3 : 277–285.

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Fatigue

Description

Fatigue is a feeling of exhaustion or loss of strength. The duration of fatigue for a patient with cancer has been found to last from one to two times the length of time between diagnosis and completion of treatment, so it is common for fatigue to persist beyond a patient's treatment regimen.

Causes

Many people experience fatigue as a side effect of cancer treatment. Both chemotherapy and radiation therapy are associated with fatigue. Scientists believe fatigue also occurs because the body is devoting so much of its energy fighting the cancer that it has little left over for daily life. Often the feelings of exhaustion are more intense immediately following a cancer treatment, but they gradually ease over time as the body gains strength.

During chemotherapy, anti-cancer drugs kill both cancer cells and healthy cells, including red blood cells. This can lead to anemia , or low red blood cell counts, which causes fatigue. Chemotherapy agents also attack white blood cells, weakening the immune system.

Medications, pain, depression , and the stress of the diagnosis and treatment are other factors that result in fatigue.

Treatments

If anemia is a problem, physicians may prescribe iron supplements or drugs, such as erythropoietin , to stimulate blood cell growth. In some cases, blood transfusions may be necessary.

Many people with cancer find that they must pace themselves, alternating periods of activity with small naps. Going to bed earlier also seems to help.

Research has shown that people who exercise experience less cancer-related fatigue. Walking or using an exercise bicycle are good choices. For those who have severe weakness, even a few minutes of gentle stretching in bed can make a difference.

Eating nutritious food is another way to get an energy boost to better fight cancer. Include a variety of fruits and vegetables, whole grains and plenty of protein, if nausea and vomiting are not a problem. High-calorie liquid meals can help offset severe weight loss for those who cannot tolerate solid foods. Drinking plenty of water also helps prevent diarrhea and dehydration, which add to fatigue.

Alternative and complementary therapies

Yoga has proven to be highly effective in reducing stress, thereby increasing energy and helping people to relax and sleep better.

Marijuana has been used to help ease nausea in cancer patients. Since a loss of appetite can cause weakness and fatigue, marijuana may help indirectly. Most states do not permit the use of marijuana for medical reasons. Physicians will be aware of these regulations.

Other complementary therapies, such as massage, aromatherapy, meditation, or prayer, help people with cancer relax, easing their worries and ultimately combatting fatigue.

See Also Complementary cancer therapies

Resources

BOOKS

Clegg, Holly B., and Gerald Miletello, MD. Eating Well Through Cancer. Baton Rouge: Holly B. Clegg Inc., 2001.

Hassett Dahm, Nancy, and Robert Schirmer. Mind, Body and Soul: A Guide to Living with Cancer. New York: Taylor Hill Publishing, 2000.

PERIODICALS

Dimeo, F. C. et al. "Effects of Physical Activity on the Fatigue and Psychologic Status of Cancer Patients During Chemotherapy." Cancer 85, no. 10 (May 15, 1999): 2273-7.

ORGANIZATIONS

American Cancer Society. 1599 Clifton Road, Atlanta, GA30329. (800) ACS-2345. <http://www.cancer.org>. CancerFatigue.org. Oncology Nursing Society, 501 HolidayDr., Pittsburgh, PA 15220. (412) 921-7373. <http://www.cancerfatigue.org>.

OTHER

"Fatigue." American Cancer Society June 2001. 28 June 2001<http://www3.cancer.org/cancerinfo/>.

Melissa Knopper, M.S.

KEY TERMS

Anemia

—A condition that occurs when the body has low red blood cell counts. It can cause fatigue.

Erythropoietin

—A drug used to stimulate blood cell growth when a person has anemia.

fa·tigue / fəˈtēg/ • n. 1. extreme tiredness, typically resulting from mental or physical exertion or illness: he was nearly dead with fatigue. ∎  a reduction in the efficiency of a muscle or organ after prolonged activity. ∎  weakness in materials, esp. metal, caused by repeated variations of stress: metal fatigue. ∎  a lessening in one's response to or enthusiasm for something, typically as a result of overexposure to it: museum fatigue. 2. (also fa·tigue de·tail) a group of soldiers ordered to perform menial, nonmilitary tasks, sometimes as a punishment. ∎  (fatigues) loose-fitting clothing, typically khaki, olive drab, or camouflaged, of a sort worn by soldiers: battle fatigues. • v. (-tigues , -tigued , -ti·guing ) [tr.] (often be fatigued) cause (someone) to feel tired or exhausted: they were fatigued by their journey. ∎  reduce the efficiency of (a muscle or organ) by prolonged activity. ∎  weaken (a material, esp. metal) by repeated variations of stress.

fatigue in engineering, microscopic cracking of materials, especially metals, after repeated applications of stress. Fissures may be formed within pieces of metal during their manufacture when, while cooling from the molten state, they shrink and tensile stresses arise. Once a crack has started it spreads under repeated stress until the metal ruptures. Examples of fatigue are found in steel rails, beams, and girders. Metallic fatigue resulted in the catastrophes encountered by many of the Liberty ships built during World Wars I and II and the crashes of a number of the earliest jet aircraft constructed. Materials used in construction are tested for fatigue strength, or endurance limit, by being subjected mechanically to cyclic applications of stress. Steel parts are sometimes treated by shot blasting to increase their fatigue resistance.

fatigue n.
1. (fatigues) loose-fitting clothing, typically khaki, olive drab, or camouflaged, of a sort worn by soldiers when performing such menial tasks or on active duty: battle fatigues.

2. (fatigues) a menial task of a nonmilitary nature performed by a soldier, sometimes as a punishment: we're on cookhouse fatigues, sir.

3. (fatigue party) a group of soldiers ordered to do such a duty.

4. weakness in materials, especially metal, caused by repeated variations of stress: metal fatigue.
v. weaken (a material, especially metal) by repeated variations of stress.

fatigue (fă-teeg) n.
1. mental or physical tiredness, following prolonged or intense activity. Muscle fatigue may be due to the waste products of metabolism accumulating in the muscles faster than they can be removed by the venous blood.

2. the inability of an organism, an organ, or a tissue to give a normal response to a stimulus until a certain recovery period has elapsed.

fatigue weariness; fatiguing duty or labour XVII (mil. sense XVIII). — F., f. (O)F, fatiguer vb. (whence fatigue vb. XVII) — L. fatīgāre exhaust, weary, f. *fatis in ad fatim, affatim abundantly, enough, prop. ‘to bursting’ (cf. fatiscāre, -ārī burst open, gape open).

154. Fatigue

See also 372. SLEEP .

hebetude

the state, condition, or quality of being dull, enervated, or lethargie. —hebetudinous , adj.

kopophobia

an abnormal fear of mental or physical exhaustion.

ponophobia

an abnormal fear of fatigue, especially through overworking.

fatigue A decline in the level of response of tissues (such as muscle), cells, etc., to nervous stimulation, which occurs after prolonged and continued stimulation of these structures.

fatigue See accommodation.

fatigue See ACCOMMODATION.

fatigue •fatigue, Grieg, intrigue, league, renege •colleague •Blitzkrieg, Sitzkrieg