A headache is a disorder in which a person feels pain or discomfort somewhere in the face, neck, or scalp. The brain and the skull are not the sources of headache pain because they do not contain pain-sensitive nerve endings. The sources of headache pain are nerve endings in the scalp, face, throat, the muscles of the head, and blood vessels at the base of the brain. When any of these nerve endings are triggered by stress, tension in the muscles, inflammation, or dilation of the blood vessels in the head, the person may experience pain.
Doctors have described over 130 different types of headaches. They can be classified into primary and secondary headaches. Primary headaches are those in which the headache is not caused by an injury, infection, or other disorder, but rather by some type of disturbance in the brain's relationship to the body. They include migraine headaches, tension headaches, cluster headaches, and so-called ordinary headaches.
Secondary headaches are caused by an injury or some other illness. There are at least 300 known causes of secondary headaches. The major types of secondary headaches are post-traumatic headaches, sinus headaches, reactive headaches, and rebound headaches.
It is possible for a person to suffer from more than one type of headache.
Headache pain can vary in location, severity, duration, and quality (dull, piercing, throbbing, etc.) depending on the cause or type of the headache. The main characteristics of the major types of headaches are described below.
When to See the Doctor
Most headaches go away by themselves or with over-the-counter pain relievers in a few hours. Some headaches, however, indicate a serious health problem. Anyone with any of the following symptoms should see their doctor or go to the emergency room at once:
- The headache comes on suddenly and has a violent or explosive quality.
- The headache feels like the worst one the person has ever had.
- The person is experiencing slurred speech, change in vision, problems moving arms or legs, loss of balance, confusion, or memory loss along with the headache.
- The headache is getting worse over a twenty-four-hour period.
- The person has fever, stiff neck, nausea, and vomiting along with the headache.
- The person is over age fifty and the headaches just began.
- The person is losing consciousness or is having convulsions.
- The person suffered a head injury before the headache.
- The headache is so severe that it wakes the person from sleep.
- The headache has lasted longer than a few days.
- Migraine headaches: Migraine headaches are caused by disturbances in the central nervous system leading to swelling of the blood vessels in the brain and severe pain. The pain affects only one side of the head in 60 percent of cases, and is often accompanied by nausea, vomiting, and extreme sensitivity to light. There are two basic types of migraine: migraine with aura (visual disturbances preceding the pain of the headache) and migraine without aura. The person may be sick for one to two full days.
- Tension headaches: These are characterized by a sensation of tightness or pressure in the head and are often accompanied by muscle tension in the neck. Tension headaches may occur on a daily basis or only at random. They usually last for several hours.
- Cluster headaches: Cluster headaches are sharp and extremely painful headaches that tend to occur several times per day for months and then go away for long periods of time. They are the rarest type of primary headache.
- Ordinary headaches: Some doctors think that ordinary headaches are actually a mild form of migraine. These headaches usually occur at random, are not associated with a head injury or other illness, and usually go away with rest and mild pain relievers.
- Post-traumatic headaches: Post-traumatic headaches occur in as many as 88 percent of people with a closed head injury and 60 percent of people with a whiplash injury. This type of headache is accompanied by pain in the neck and shoulders, dizziness, mood or personality changes, and sleep disturbances.
- Sinus headaches: These are associated with post-nasal drip, sore throat, and a discharge from the nose. The pain of a sinus headache is usually experienced in the front of the face and head, and is usually worse in the morning than later in the day.
- Reactive headaches: Reactive headaches are triggered by an irritant in the environment or another illness. There are hundreds of possible triggers, ranging from the weather, pollen, dust, and other allergens, to colds, flu, eyestrain, and stomach upsets.
- Rebound headaches: Rebound headaches are a reaction to overuse of over-the-counter medications for pain relief, decongestants, or muscle relaxants. They can also be caused by withdrawal from caffeine or alcohol.
Headaches are a very common problem in the general population. Almost everyone gets an occasional headache, particularly when they are short on sleep, emotionally stressed, have skipped a meal, or are suffering from flu or a cold. Children can get headaches as well as adults; by age six, 31 percent of children have had at least one headache; by the time a child is fifteen, the number has risen to 70 percent. Between 60 and 80 million Americans suffer from frequent headaches but only 30 percent of these people consult a doctor for treatment.
According to the National Institutes of Health (NIH), children in the United States miss 1 million days of school each year because of headaches while adults miss 160 million days of work. Headaches cost the economy an estimated $30 billion each year in medical expenses.
Headaches affect people of all races equally; however, the gender ratio varies depending on the type of headache. Women are three times as likely as men to suffer from migraine headaches, but men are ten times as likely as women to get cluster headaches.
The basic causes of headaches include disturbances in the central nervous system leading to irritation of the blood vessels in the head; tension in the muscles of the head and neck; infections; allergens and other environmental triggers; overuse of or withdrawal from drugs; lack of sleep; clenching or grinding the teeth; menstruation; depression or anxiety; certain foods; and head injuries.
Less common but dangerous causes of headaches include:
- Brain tumors
- An infection of the brain (encephalitis or meningitis)
- Bursting of a blood vessel in the brain
In addition to the pain of a headache, people may experience nausea, vomiting, diarrhea and other digestive symptoms; dizziness, loss of balance, and visual disturbances; mood and personality changes; extreme tiredness; muscle cramps in the neck and shoulders; inability to concentrate; and extreme sensitivity to light or noise.
Diagnosing headaches can be complicated because there are so many potential causes and because some people have more than one type of headache. In addition to examining the patient's head, neck, mouth, and throat in the office, most doctors will ask the patient to keep a headache diary, noting the time when a headache occurs, how long it lasts, other symptoms that accompany the headache, the quality and location of the pain, possible triggers, and other illnesses that the patient had at the time.
In some cases the doctor will order a computed tomography (CT) scan or a magnetic resonance imaging (MRI) of the patient's head. If encephalitis or meningitis are suspected, the doctor may order a spinal tap.
Treatment depends on the type of headache. Secondary headaches are treated by removing or avoiding the underlying cause, whether a head or whiplash injury, environmental trigger, food allergy, overuse of alcohol or medications, sinus infection, eyestrain, or other problem.
Primary headaches are usually treated by appropriate medications:
- Migraine headaches can be treated either by medications taken before an attack to stop it or reduce its severity, or by medications taken to relieve the headache after it begins. Preventive medications include a group of drugs called triptans; certain antidepressants; and antiepileptic drugs. After the headache starts, the patient may be treated with over-the-counter pain relievers like acetaminophen, naproxen, or ibuprofen, or prescription medications like ergotamine. Most patients with migraine are helped by resting in a quiet darkened room.
- Tension headaches: Usually respond well to over-the-counter pain relievers or to prescription pain relievers containing codeine. Hot showers and rest are also recommended for self-care at home. Some patients are also helped by biofeedback, relaxation training, yoga, or massage therapy. In some cases the doctor may recommend psychotherapy if the patient's headaches are related to emotional stress.
- Cluster headaches: The triptans are effective in treating cluster headaches in many patients, as is oxygen inhalation. Because cluster headaches often come on very quickly, the triptans are usually given by injection rather than by mouth.
- Ordinary headaches: Usually treated in the same way as tension headaches.
The prognosis for a headache depends on whether it is primary or secondary and its underlying cause or causes. Most ordinary headaches can be treated at home with few long-term side effects or complications. Cluster headaches, recurrent tension headaches, and migraines require long-term follow-up with a doctor. Cluster headaches are more difficult to treat successfully than either migraines or recurrent tension headaches.
People can lower their risk of headaches in several ways:
- Getting enough rest, eating a healthful diet without skipping meals, and exercising regularly.
- Taking occasional work or study breaks, particularly if working at a computer or reading for long periods of time.
- Having the eyes checked regularly, particularly if the person wears prescription eyeglasses or contacts.
- Avoiding overuse of over-the-counter pain relievers, decongestants, caffeine, or alcohol.
- Quitting smoking.
- Practicing relaxation techniques, yoga, meditation, or other approaches to stress management.
- Avoiding allergens, foods, or other factors known to trigger headaches whenever possible.
Headaches are likely to be an ongoing health problem in the general population, if only because they have so many possible causes and
environmental triggers. Research into the causes of migraine headaches has yielded new insights since the late 1990s. Clinical trials include research into the causes of cluster headaches, which are still not well understood; evaluations of newer triptan drugs in treating migraine and cluster headaches; studies of the factors that affect the prognosis for recovery from headaches; studies comparing different types of treatment for rebound headaches; and studies of yoga, acupuncture, massage therapy, and other alternative treatments.
SEE ALSO Alcoholism; Allergies; Brain tumors; Common cold; Concussion; Encephalitis; Influenza; Meningitis; Stroke; Whiplash
WORDS TO KNOW
Aura: A symptom that precedes migraine headaches in some people. The person may see flashing or zigzag lights, or have other visual disturbances.
Biofeedback: An alternative treatment for headaches (and other conditions) that consists of teaching patients to consciously control their blood pressure, muscle tension, temperature, and other body processes.
Migraine: A type of primary headache characterized by severe pain, nausea and vomiting, and sensitivity to light. It may occur on only one side of the head.
Withdrawal: A collection of signs and symptoms that appear when a drug (including caffeine and nicotine) that a person has used for a long time is suddenly discontinued.
Diamond, Seymour, and Merle Lea Diamond. A Patient's Handbook of Headache and Migraine. Newtown, PA: Handbooks in Health Care Co., 2001.
Forshaw, Mark. Understanding Headaches and Migraines. Hoboken, NJ: John Wiley and Sons, 2004.
Robbins, Lawrence D., and Susan S. Lang. Headache Help: A Complete Guide to Understanding Headaches and the Medicines that Relieve Them, rev. ed. Boston: Houghton Mifflin Co., 2000.
Jaret, Peter. “A Hidden Cause of Headache Pain.” New York Times, May 24, 2008. Available online at http://www.health.nytimes.com/ref/health/healthguide/esn-headache-ess.html (accessed on August 15, 2008). This is an article about the rebound effect.
American Academy of Family Physicians (AAFP). Headaches. Available online at http://www.familydoctor.org/online/famdocen/home/tools/symptom/502.html (reviewed 2008; accessed on August 15, 2008). This is a flow chart or
diagram intended to help the reader evaluate the symptoms and possible causes of their headache.
National Headache Foundation (NHF). Headache Topic Sheets. Available online at http://www.headaches.org/education/Headache_Topic_Sheets (accessed on August 15, 2008). This is a page with links to over a hundred specific topics related to headaches.
National Institute of Neurological Disorders and Stroke (NINDS). Headache: Hope through Research. Available online at http://www.ninds.nih.gov/disorders/headache/detail_headache.htm (updated July 31, 2008; accessed on August 15, 2008).
National Pain Foundation. Help for Headaches. Available online at http://www.nationalpainfoundation.org/MyTreatment/articles/Headache_Overview.asp (updated March 28, 2008; accessed on August 15, 2008).
Nemours Foundation. Headaches. Available online at http://www.kidshealth.org/parent/general/aches/headache.html (updated March 2006; accessed on August 15, 2008).