Migraines are a type of headache that cause severe, throbbing pain, often accompanied by nausea, vomiting, and sensitivity to light (photophobia) or sound (phonophobia). Migraine headaches generally last between four and 72 hours. Many people experience certain symptoms prior to the onset of the head pain. Symptoms that precede and herald an upcoming headache are referred to as an "aura," and usually last under an hour.
About 1 out of 8 Americans has migraines. They usually begin during the teenage years. After puberty, migraines are more likely to affect girls and women.
Experts still aren't sure what causes these headaches. But they seem to involve a wave of unusual activity in brain nerve cells, along with changes in blood flow in the brain.
Though migraines can trigger severe pain in the head, they aren't simply headaches. They often also cause other uncomfortable symptoms, such as:
A numb or tingly feeling in your face, neck, head, or arms
You are most likely to begin developing migraine headaches between age 10 and 40, and your risk for having migraine headaches is three times greater if you're a woman. Many women find that their migraines improve or disappear altogether after age 50.
What Are the Causes of Migraines?
Research has not completely explained how migraine headaches develop. People who suffer from migraines have brain cells that seem to be overly sensitive to stimulation. Stimulation that has no effect on others -- such as intense emotion, overexertion, foods, odors, or sounds -- sets off a series of events in the brain of migraine sufferers that result in blood vessels first narrowing (constricting) and then widening (dilating). Chemicals are released which cause inflammation and pain.
The tendency to develop migraine headaches appears to be hereditary. In fact, more than 50% of people who get migraines have other family members who also suffer from migraines.
Migraine headaches are also common just before the start of each menstrual period, leading researchers to suspect that a lack of estrogen may lead to the development of migraines in women. Migraines often lessen during the early part of pregnancy, perhaps due to increased estrogen. Some women, however, continue to have problems with migraine throughout their pregnancy.