Migraines, which often begin in childhood, adolescence or early adulthood, 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 thirst and urination
• Frequent yawning

Aura

For some people, 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 lasts for 20 to 60 minutes.

Examples of migraine aura 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
• Hearing noises or music
• Uncontrollable jerking or other movements

Attack

A migraine usually lasts from four 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.

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 and hormone replacement therapy, also can worsen migraines. Some women, however, find their migraines occurring 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 lights and sun glare can induce migraines, as can loud sounds. Strong smells — including perfume, paint thinner, secondhand smoke and others — trigger migraines in some people.
• Sleep changes. Missing sleep, getting too much sleep or jet lag 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.
• 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 or fasting.
• Food additives. These include the sweetener aspartame and the preservative monosodium glutamate (MSG), found in many foods.

Several factors make you more prone to having migraines, including:

• Family history. If you have a family member with migraines, then you have a good chance of developing them too.
• Age. Migraines can begin at any age, though the first often occurs during adolescence. Migraines tend to peak during your 30s, and gradually become less severe and less frequent in the following decades.
• Sex. Women are three times more likely to have migraines.
• Hormonal changes. For women who have migraines, headaches might begin just before or shortly after onset of menstruation. They might also change during pregnancy or menopause. Migraines generally improve after menopause.

Taking combination painkillers, such as Excedrin Migraine for more than 10 days a month for three months or in higher doses can trigger serious medication-overuse headaches. The same is true if you take aspirin or ibuprofen (Advil, Motrin IB, others) for more than 15 days a month or triptans, sumatriptan (Imitrex, Tosymra) or rizatriptan (Maxalt), for more than nine days a month.

Medication-overuse headaches occur when medications stop relieving pain and begin to cause headaches. You then use more pain medication, which continues the cycle.