A migraine headache is a pulsating or throbbing pain that usually ranges from moderate to severe. It can affect one or both sides of the head. It is worsened by physical activity, light, sounds, or smells and is accompanied by nausea, vomiting, and sensitivity to sounds and light.

• Migraines may be triggered by lack of sleep, changes in the weather, hunger, excessive stimulation of the senses, stress, or other factors.
• Doctors base the diagnosis on typical symptoms.
• There is no cure for migraines, but drugs to stop the progression of migraines, pain relievers (analgesics), and drugs to prevent migraines can help control them.

Although migraines can start at any age, they usually begin during puberty or young adulthood. In most people, migraines recur periodically (fewer than 15 days a month). After age 50, headaches usually become significantly less severe or resolve entirely. Migraines are 3 times more common among women. In the United States, about 18% of women and 6% of men have a migraine at some time each year.

Migraine may become chronic. That is, headaches occur more than 15 days a month. These headaches often develop in people who overuse drugs to treat migraines.

Migraines tend to run in families. More than half the people who have migraines have close relatives who also have them.

Causes

Migraines occur in people whose nervous system is more sensitive than that of other people. That is, nerve cells in the brain are easily stimulated, producing electrical activity. As electrical activity spreads over the brain, various functions, such as vision, sensation, balance, muscle coordination, and speech are temporarily disturbed. These disturbances cause the symptoms that occur before the headache (called the aura). The headache occurs when the 5th cranial (trigeminal) nerve is stimulated. This nerve sends impulses (including pain impulses) from the eyes, scalp, forehead, upper eyelids, mouth, and jaw to the brain. When stimulated, the nerve may release substances that cause painful inflammation in the blood vessels of the brain (cerebral blood vessels) and the layers of tissues that cover the brain (meninges). The inflammation accounts for the throbbing headache, nausea, vomiting, and sensitivity to light and sound.

A rare subtype of migraine called familial hemiplegic migraine is associated with genetic defects on chromosomes 1, 2, and 19. The role of genes in the more common forms of migraine is under study.

Estrogen, the main female hormone, appears to trigger migraines, possibly explaining why migraines are more common among women. During puberty (when estrogen levels increase), migraines become much more common among girls than among boys. Some women have migraines just before, during, or just after menstrual periods. As menopause approaches (when estrogen levels are fluctuating), migraines become particularly difficult to control. Oral contraceptives (which contain estrogen) and estrogen therapy may make migraines worse and may increase the risk of stroke in women who have migraines with an aura. Other triggers include the following:

• Lack of sleep, including insomnia
• Changes in the weather, particularly barometric pressure
• Red wine
• Certain foods
• Hunger (as when meals are skipped)
• Excessive stimulation of the senses (for example, by flashing lights or strong odors)
• Stress

Head injuries, neck pain, or a problem with the joint of the jaw (temporomandibular joint disorder) sometimes trigger or worsen migraines.

Symptoms

In a migraine, pulsating or throbbing pain is usually felt on one side of the head, but it may occur on both sides. The pain may be moderate but is often severe and incapacitating. Physical activity, light, sounds, or smells may make the headache worse. This increased sensitivity makes many people retreat to a dark, quiet room and lie down until the headache subsides. The headache is often accompanied by nausea, sometimes with vomiting. Severe attacks can be incapacitating, disrupting family and work life.

People often have sensations warning them that an attack is about to begin. These sensations, called the prodrome, may include mood changes, loss of appetite, and nausea.

In about 25% of people, migraines are preceded by an aura. The aura involves temporary, reversible disturbances in vision, sensation, balance, muscle coordination, or speech. People may see jagged, shimmering, or flashing lights or develop a blind spot with flickering edges. Less commonly, people experience tingling sensations, loss of balance, weakness in an arm or a leg, or difficulty talking. The aura lasts minutes to an hour before and may continue after the headache begins. Some people experience an aura but have only a mild or no headache. These mild headaches are similar to tension-type headaches.

Migraine attacks may last for hours to a few days (typically 4 hours to 3 days). Usually, they subside during sleep. They may occur frequently for a long time, then disappear for many weeks, months, or even years.

Did You Know... Only ¼ of people have sensations that warn them that a migraine is about to begin. Taking pain relievers too often can make migraines worse.

Diagnosis

Doctors diagnose migraines when symptoms are typical and results of a physical examination (which includes a neurologic examination) are normal.

No procedure can confirm the diagnosis. If headaches have developed recently or if the pattern of symptoms has changed, computed tomography (CT) or magnetic resonance imaging (MRI) of the head may be done to exclude other disorders. For example, an imaging test may be done to check for stroke in older people who have migraines with an aura, especially when the migraine is mild or does not occur.

Prevention

When treatment does not prevent people from having frequent or incapacitating migraines, taking drugs every day to prevent migraine attacks helps. Taking preventive drugs may help people who are taking other migraine drugs too often and who need to reduce their use.

Beta-blockers, such as propranolol, are often used. The anticonvulsants topiramate and divalproex and the tricyclic antidepressant amitriptyline are also effective. The choice of a preventive drug is based on the side effects of the drug and on other disorders present. For example, people who are overweight may be given topiramate, which can promote weight loss. People with depression or insomnia may be given amitriptyline (see Mood Disorders: Drugs Used to Treat Depression).

Treatment

Migraines cannot be cured, but they can be controlled.

Doctors encourage people to keep a headache diary. In it, people write down the number and timing of attacks, possible triggers, and their response to treatment. With this information, triggers may be identified and eliminated when possible, and doctors can better plan and adjust treatment. Behavioral interventions (such as relaxation, biofeedback, and stress management) are used to control migraine attacks, especially when stress is a trigger or when people are taking too many drugs to control the migraines.

Some drugs stop a migraine from progressing. Some are taken to control the pain. Others are taken to prevent migraines.

When migraines are or become severe, drugs that can stop the migraine from progressing are used. They are taken as soon as people sense a migraine is beginning. They include the following:

• Triptans (5-hydroxytryptamine [5-HT], or serotonin, agonists) are usually used. Triptans specifically target the receptors that stimulate nerves supplying the meninges and cerebral blood vessels, where migraine symptoms originate. These drugs are most effective when taken as soon as the migraine begins. They may be taken by mouth, inhaled, or injected under the skin.
• Dihydroergotamine is used to stop severe, persistent migraines.
• Prochlorperazine, an antiemetic, may be used when people cannot tolerate triptans or dihydroergotamine.

Because triptans and dihydroergotamine cause blood vessels to narrow (constrict), they are not recommended for people who have angina, coronary artery disease, or uncontrolled high blood pressure. If older people or people with risk factors for coronary artery disease need to take these drugs, they must be monitored closely.

If migraines are usually accompanied by nausea, a drug to relieve nausea (antiemetic) may also be taken. Antiemetics alone may stop mild or moderate migraines from progressing.

For less severe migraines, analgesics with or without caffeine can be useful. They can be taken as needed during a migraine, with or instead of a triptan.

Overuse of analgesics, caffeine (in analgesic preparations or in caffeinated beverages), or triptans can lead to daily, more severe migraines. Such headaches, called medication overuse headaches, occur when these drugs are taken more than 2 to 3 days each week. Missing or reducing a dose or taking it late may trigger or worsen a migraine.

When other treatments are ineffective in people with severe migraines, opioids may be needed (see Opioid Analgesics). Opioids are a last resort.

Drugs Used to Treat Migraines Type Examples Some Side Effects Prevention Anticonvulsants Divalproex Topiramate Hair loss, stomach upset, liver dysfunction, a tendency to bleed, tremors, and weight gain (see Seizure Disorders: Drugs Used to Treat Seizures) With topiramate, weight loss, confusion, and depression Beta-blockers Atenolol Metoprolol Nadolol Propranolol Timolol Spasm of the airways (bronchospasm), fatigue, insomnia, worsening of heart failure, and sexual dysfunction With some beta-blockers, unfavorable effects on lipid (fat) levels (see High Blood Pressure: Antihypertensive Drugs) Calcium channel blockers Verapamil Dizziness, low blood pressure, and weakness With verapamil, constipation (see High Blood Pressure: Antihypertensive Drugs) Tricyclic antidepressants Amitriptyline Drowsiness, weight gain, increased heart rate, dry mouth, confusion, and constipation (see Mood Disorders: Drugs Used to Treat Depression) Treatment of severe migraines Antiemetic drugs Metoclopramide Prochlorperazine Low blood pressure, drowsiness, and muscle spasms Ergot derivatives Dihydroergotamine Nausea, vomiting, minor muscle cramping, and, rarely, chest pain due to an inadequate blood supply to the heart muscle (angina) Triptans (5-hydroxytryptamine [5-HT] agonists) Almotriptan Eletriptan Naratriptan Rizatriptan Sumatriptan Zolmitriptan Flushing, tingling, dizziness, drowsiness, nausea, a sense of pressure in the throat or chest, and, rarely, angina Opioids Codeine Meperidine Oxycodone Slowing of breathing, constipation, retention of urine, drowsiness, and nausea (see Pain: Opioid Analgesics) Treatment of mild to moderate migraines Analgesic Acetaminophen Rebound headache if the dose is increased and, occasionally, skin rash Nonsteroidal antiinflammatory drugs (NSAIDs) Aspirin Indomethacin Naproxen Worsening of headache if the dose is increased and later suddenly decreased. With indomethacin, worsening of depression, seizures, and tremors with decreased mobility and muscle stiffness and, in older people, dizziness and confusion

Last full review/revision April 2008 by Stephen D. Silberstein, MD