A migraine is a headache that can cause severe throbbing pain or a pulsing sensation, usually on one side of the head. It's often accompanied by nausea, vomiting, and extreme sensitivity to light and sound. Migraine attacks can last for hours to days, and the pain can be so severe that it interferes with your daily activities.

For some people, a warning symptom known as an aura occurs before or with the headache. An aura can include visual disturbances, such as flashes of light or blind spots, or other disturbances, such as tingling on one side of the face or in an arm or leg and difficulty speaking.

Medications can help prevent some migraines and make them less painful. The right medicines, combined with self-help remedies and lifestyle changes, might help.

Symptoms

Migraines, which affect children and teenagers as well as adults, can progress through four stages:
prodrome, aura, attack and post-drome. Not everyone who has migraines goes through all stages.

Prodrome

One or two days before a migraine, you might notice subtle changes that warn of an upcoming migraine, including:

• Constipation
• Mood changes, from depression to euphoria
• Food cravings
• Neck stiffness
• Increased urination
• Fluid retention
• Frequent yawning

Aura

For some people, an aura might occur before or during migraines. Auras are reversible symptoms of the nervous system. They're usually visual but can also include other disturbances. Each symptom usually begins gradually, builds up over several minutes and can last up to 60 minutes.

Examples of migraine auras include:

• Visual phenomena, such as seeing various shapes, bright spots or flashes of light
• Vision loss
• Pins and needles sensations in an arm or leg
• Weakness or numbness in the face or one side of the body
• Difficulty speaking

Attack

A migraine usually lasts from 4 to 72 hours if untreated. How often migraines occur varies from person to person. Migraines might occur rarely or strike several times a month.

During a migraine, you might have:

• Pain usually on one side of your head, but often on both sides
• Pain that throbs or pulses
• Sensitivity to light, sound, and sometimes smell and touch
• Nausea and vomiting

Post-Drome

After a migraine attack, you might feel drained, confused and washed out for up to a day. Some people report feeling elated. Sudden head movement might bring on the pain again briefly.

When to see a doctor

Migraines are often undiagnosed and untreated. If you regularly have signs and symptoms of migraine, keep a record of your attacks and how you treated them. Then make an appointment with your doctor to discuss your headaches.

Even if you have a history of headaches, see your doctor if the pattern changes or your headaches suddenly feel different.

See your doctor immediately or go to the emergency room if you have any of the following signs and symptoms, which could indicate a more serious medical problem:

• An abrupt, severe headache like a thunderclap
• Headache with fever, stiff neck, confusion, seizures, double vision, numbness or weakness in any part of the body, which could be a sign of a stroke
• Headache after a head injury
• A chronic headache that is worse after coughing, exertion, straining or a sudden movement
• New headache pain after age 50

Causes

Though migraine causes aren't fully understood, genetics and environmental factors appear to play a role.

Changes in the brainstem and its interactions with the trigeminal nerve, a major pain pathway, might be involved. So might imbalances in brain chemicals — including serotonin, which helps regulate pain in your nervous system.

Researchers are studying the role of serotonin in migraines. Other neurotransmitters play a role in the pain of migraine, including calcitonin gene-related peptide (CGRP).

Migraine triggers

There are a number of migraine triggers, including:

• Hormonal changes in women

  Fluctuations in estrogen, such as before or during menstrual periods, pregnancy and menopause, seem to trigger headaches in many women. Hormonal medications, such as oral contraceptives, also can worsen migraines. Some women, however, find that their migraines occur less often when taking these medications.

• Drinks

  These include alcohol, especially wine, and too much caffeine, such as coffee.

• Stress

  Stress at work or home can cause migraines.

• Sensory stimuli

  Bright or flashing lights can induce migraines, as can loud sounds. Strong smells — such as perfume, paint thinner, secondhand smoke and others — trigger migraines in some people.

• Sleep changes

  Missing sleep or getting too much sleep can trigger migraines in some people.

• Physical factors

  Intense physical exertion, including sexual activity, might provoke migraines.

• Weather changes

  A change of weather or barometric pressure can prompt a migraine.

• Allergic contact dermatitis

  This condition is common in people with atopic dermatitis. Allergic contact dermatitis is an itchy rash caused by touching substances you're allergic to. The color of the rash varies depending on your skin color.

• Medications

  Oral contraceptives and vasodilators, such as nitroglycerin, can aggravate migraines.

• Foods

  Aged cheeses and salty and processed foods might trigger migraines. So might skipping meals.

• Food Additives

  These include the sweetener aspartame and the preservative monosodium glutamate (MSG), found in many foods.