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Diagnosis

Diagnosis

Diagnosis is the process of identifying a disease or disorder in a person by examining the person and studying the results of medical tests.

The process of diagnosis begins when a patient appears before a doctor with a set of symptoms, such as pain, nausea, fever, or some other unusual feeling. In many cases, the diagnosis is relatively simple. The physician can decide by making a few simple observations as to the patient's problem and can prescribe a proper treatment. At other times, the symptoms may be more difficult to interpret, and making a diagnosis may require laboratory tests and other kinds of examinations.

Sources of information

In order to make a diagnosis, a physician searches for information from three major sources: the patient himself or herself, a physical examination, and a laboratory examination.

Patient information. Patient information is obtained by asking the patient a variety of questions about his or her previous health history and present symptoms. For example, the patient who is experiencing unusual pains may be asked to tell how long the pains have persisted, where they are located, the type of pain experienced, and whether the pain is constant or intermittent.

Words to Know

Benign: Noncancerous.

Biopsy: The removal and examination of tissue from a person's body.

Invasive: A technique that involves entering the body.

Laparoscope: A device consisting of a long flexible tube that contains a light source that allows a physician to look into the abdominal cavity without making a large incision in the abdominal wall.

Laparotomy: A process by which the abdominal wall is opened in order to allow a physician to look inside.

Malignant: Cancerous.

Palpation: A technique used by doctors that involves the use of fingers to touch and feel various parts of a patient's body.

Stethoscope: A device that magnifies sounds produced in the human body.

A patient's occupation may have a bearing on his or her illness. Perhaps he or she works around chemicals that may cause illness. A job that requires repeated bending and lifting may result in muscle strain or back pain. A police officer or fire fighter may have periods of boredom interrupted by periods of stress or fear.

The medical history of a patient's family may also be helpful. Some diseases are hereditary and some, although not hereditary, are more likely to occur if the patient's parent or other close relative has had such a disease. For example, the person whose father has had a heart attack is more likely to have a heart attack than is a person whose family has been free of heart disease.

Personal habits, such as smoking or drinking large amounts of alcohol, also contribute to disease. Lack of exercise, lack of sleep, and an unhealthy diet are all involved in bringing about symptoms of disease.

The physical examination. In addition to exploring the patient's clinical history, the physician will carry out a physical examination to further narrow the list of possible medical problems. The patient's temperature, blood pressure, and rate of respiration will be measured. He or she will be weighed and his or her height measured. The physician will examine the eardrums and look into the throat for signs of inflammation, infection, or other abnormal conditions.

The heart and lungs can be examined superficially (from outside the body) using a stethoscope. A stethoscope allows the physician to hear abnormalities in the heartbeat or in the functioning of the heart valves. The presence of water or other fluid in the lungs can also be heard with a stethoscope. The physician can also study sounds made by the intestines by listening to them through the stethoscope.

A physician may also use a technique called palpation, in which the physician uses his or her fingers to probe the abdomen for signs of pain or an abnormal lump or growth. The doctor also feels the neck, the area under the armpit, and other areas to locate any enlarged lymph nodes, a sign of an infection. Such probing also may bring to light the presence of a tender area previously unknown to the patient.

If the patient is complaining of an injury, the physician can carefully palpate around the injury to determine its size. He or she can bend a leg or arm to determine whether a joint has been broken. Similar techniques also reveal whether a ligament (tissue that connects bones) has been torn and if it may need surgical correction.

The laboratory examination. The physician also may decide to have laboratory tests performed on various fluids taken from the patient. The most common fluids used are blood, urine, stomach fluid, and spinal fluid. As an example, tests of the blood reveal the number of white and red blood cells. An elevated number of white blood cells indicates an infection is present, but does not pinpoint the location of the infection. Blood also carries hormones and other components that are directly affected by disease or inflammation.

The modern clinical laboratory is one of automation and high technology. At one time, a laboratory technician was required to mix together the chemicals needed for each clinical test. Newer technology requires only that a blood specimen be placed in one end of a machine. The blood is carried through the machine, where minute amounts of the chemicals are added as needed, and test results are printed out automatically. This technology also enables the measurement of blood or urine components in amounts much smaller than previous technology allowed. In some cases, a single microgram (one-millionth of a gram) can be detected in blood, urine or some other fluid.

The physician also may want to obtain X rays of an injured area to rule out the possibility of a fractured bone. (X rays are a form of electromagnetic radiation that can penetrate solids. They are used to generate images of bones and other tissues.) The presence of a heart condition can often be determined by taking an electrocardiogram (ECG), which measures the electrical activity of the heart. Changes in an ECG can indicate the presence of heart disease or give evidence of a past heart attack. CAT (computerized axial tomography) scans use X rays to produce images of one layer of hard or soft tissue, a procedure useful in detecting small

tumors. Magnetic resonance imaging (MRI) uses radio waves in a magnetic field to generate images of a layer of the brain, heart, or other organ. Ultrasound waves are also sometimes used to detect tumors.

Other laboratory specimens can be obtained by invasive techniques. An invasive technique is one in which a physician cuts open the body to look directly inside it for possible medical problems. For example, a physician who finds a suspicious lump or swelling can remove part of the lump and send it to the laboratory to be examined. The surgical removal of tissue for testing is called a biopsy. In the laboratory, the specimen is sliced very thinly, dyed to highlight differences in tissues, and examined under the microscope. This procedure enables the physician to determine whether the lump is malignant (cancerous) or benign (noncancerous).

The method of actually looking into the body cavity used to consist of a major surgical procedure called a laparotomy. In that procedure, an incision is made in the abdomen so the physician can look at each organ and other internal structures in order to determine the presence of disease or a parasite. Today, the laparotomy is carried out using a flexible tube called a laparoscope. The laparoscope is inserted into the body through a small incision. It is attached to a television monitor that gives the physician an enlarged view of the inside of the body. The flexibility of the laparoscope allows the instrument to be guided around the organs. A light attached to the scope helps the physician see each organ. The laparoscope is also equipped with a tiny device to collect specimens or to suction blood out of the abdomen.

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Diagnosis

Diagnosis

Definition

Diagnosis can be defined as the identification and labeling of a disease based on its signs and symptoms. Mental health clinicians (psychiatrists, psychologists, and psychiatric nurse practitioners) diagnose mental disorders using the criteria listed in the Diagnostic and Statistical Manual of Mental Disorders , also known as the DSM, published by the American Psychiatric Association.

Description

According to the DSM, fourth edition, text revised (the DSM-IV-TR ), the term mental disorder is unfortunate because it implies that a mental disorder is separate from a physical illness, when actually, according to the American Psychiatric Association (APA), researchers and scientists now know that that distinction is not a clear one to make. The APA argues that "there is much 'physical' in 'mental disorders' and much 'mental' in 'physical disorders,'" and continues to use the term "mental disorders" because a better term has not yet been found. The APA defines a mental disorder as "a clinically significant behavioral or psychological syndrome or pattern that occurs in an individual and that is associated with present distress or disability or with a significantly increased risk of suffering death, pain, disability, or an important loss of freedom." Many people fear that when a mental disorder is classified, people are actually classified, and the DSM-IV-TR strives to contradict this notion. The American Psychiatric Association believes their manual to be strictly a manual classifying mental disorders themselves, and does not advocate the use of the diagnoses to discriminate.

The manual lists various criteria for each mental disorder included in the book. When an individual seeks the help of a mental health clinician, the clinician interviews the client (along with family members when appropriate), gathers a medical history, and may administer psychological evaluations (various checklists or tests that the patient may complete) in order to establish a diagnosis. Once the clinician has gathered the necessary information, a diagnosis based on the symptoms may be assigned from the DSM.

One of the main purposes of diagnosis is to guide treatment planning. If doctors know that a particular disorder has shown to be treated effectively with a drug or with a specific therapy, then the best practice can be applied to a new case of that disorder. The diagnosis also helps to establish a prognosis for the patient and his or her family, and it helps to enable communication among the professionals (including insurers) involved in a patient's care. Additionally, a formal diagnosis as recognized by the DSM may be necessary in order for insurers to pay for medical services. The act of labeling a mental disorder may have unintended effects for the person with the disorder, however. Although the DSM states that its diagnoses do not label people, in reality, many people who have received diagnoses of mental disorders may feel affected by the label their disorder has been given. People diagnosed with mental disorders may feel stigmatized, and that others' perceptions of themas well as their self-perceptions have changed as a result of their diagnosis.

See also Assessment and diagnosis; Stigma

Resources

BOOKS

Allen, John J. B. "DSM-IV." In Encyclopedia of Mental Health, edited by Howard S. Friedman. San Diego, CA: Academic Press, 1998.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. Fourth edition, text revised. Washington DC: American Psychiatric Association, 2000.

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diagnosis

diagnosis, determination of the nature of a disease or ailment. A clinical diagnosis is based on the medical history and physical examination of the patient: it may be confirmed with X-Rays, CAT Scans (Computerized Axial Tomography), MRI (Magnetic Resonance Imaging), and other laboratory tests. Diagnosis by physical examination includes ascertaining temperature, pulse, and blood pressure and involves the use of palpation, to detect enlarged organs and other abnormalities; tapping, to delineate some of the internal organs; and listening, to interpret sounds from organs such as the heart and lungs. Instruments that facilitate physical examination include the sphygmomanometer for blood pressure; the stethoscope for listening to the heart and lungs; the ophthalmoscope to examine the inner eye; and the laryngoscope and bronchoscope to view the larynx, windpipe, and other air passages. Recent innovations in electronics have made it possible for any of these devices to be fitted with video cameras and lights, so that the interior of the body can be viewed on video monitors and recorded on videotape for future reference. In diagnostic tests, the blood, urine, tissues, and other excretions and secretions of the body are examined for evidence of chemical imbalance, cellular change, and the presence of pathogenic organisms. Exploratory surgery and the insertion of visual equipment through a small incision (e.g., laparoscopy and arthroscopy) may be used to assist in diagnosis.

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diagnosis

diagnosis (dy-ăg-noh-sis) n. the process of determining the nature of a disorder by considering the patient's signs and symptoms, medical background, and – when necessary – results of laboratory tests and X-ray examinations. differential d. diagnosis of a condition whose signs and/or symptoms are shared by various other conditions. See also prenatal diagnosis. Compare prognosis.
diagnostic (dy-ăg-noss-tik) adj.

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diagnosis

di·ag·no·sis / ˌdīəgˈnōsis/ • n. (pl. -ses / -ˌsēz/ ) 1. the identification of the nature of an illness or other problem by examination of the symptoms: early diagnosis and treatment are essential | a diagnosis of Crohn's disease was made. 2. the distinctive characterization in precise terms of a genus, species, or phenomenon.

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diagnosis

diagnosis XVII. — modL. — Gr. diāgnōsis, f. diagignṓskein distinguish, discern, f. DIA- + gignṓskein perceive (see KNOW).

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diagnosis

diagnosisglacis, Onassis •abscess •anaphylaxis, axis, praxis, taxis •Chalcis • Jancis • synapsis • catharsis •Frances, Francis •thesis • Alexis • amanuensis •prolepsis, sepsis, syllepsis •basis, oasis, stasis •amniocentesis, anamnesis, ascesis, catechesis, exegesis, mimesis, prosthesis, psychokinesis, telekinesis •ellipsis, paralipsis •Lachesis •analysis, catalysis, dialysis, paralysis, psychoanalysis •electrolysis • nemesis •genesis, parthenogenesis, pathogenesis •diaeresis (US dieresis) • metathesis •parenthesis •photosynthesis, synthesis •hypothesis, prothesis •crisis, Isis •proboscis • synopsis •apotheosis, chlorosis, cirrhosis, diagnosis, halitosis, hypnosis, kenosis, meiosis, metempsychosis, misdiagnosis, mononucleosis, myxomatosis, necrosis, neurosis, osmosis, osteoporosis, prognosis, psittacosis, psychosis, sclerosis, symbiosis, thrombosis, toxoplasmosis, trichinosis, tuberculosis •archdiocese, diocese, elephantiasis, psoriasis •anabasis • apodosis •emphasis, underemphasis •anamorphosis, metamorphosis •periphrasis • entasis • protasis •hypostasis, iconostasis

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