More recently, researchers have begun to believe that the brain may actually be causing the problem, although it's not as well-defined. A neurologist at Albert Einstein College of Medicine in New York told FDA Consumer magazine earlier this month that changes in the brain may trigger the blood-flow changes. And brain chemicals and the channels in nerve cells that determine the movement of minerals across them may contribute. There's no question that the vessels dilate and constrict in the process. But whether that's the cause is uncertain.

Migraine sufferers, called migraineurs, each have their own triggers. People who successfully learn what, if any, their own triggers are can go a long way toward avoiding migraine. In fact, avoiding triggers and taking medications are the heart of migraine treatment.

Baggaley treats migraineurs four days a week at the U. headache clinic. She calls migraine a disease and headache a symptom. Migraine, she says, is different from other types of headaches, like sinus or tension. And often, she says, people assume they have one of those when it's actually migraine. The condition is underdiagnosed.

"A migraine has many different facets. It's a multimechanism disease that involves blood vessels, the neurochemistry of the brain and pain receptors. If you can't stop it you get more headache. And the medicines people take for headache treatment can trigger migraine. The earlier we can intervene and understand what triggers it, people get to be the champion of their disease versus the victim."

Migraine experts tell patients to keep a diary of their headaches so they can identify what triggers their migraine. Many people have multiple triggers. For some it's fumes or perfumes, while someone else can't stand the flash of sunlight as they drive along tree-lined streets.

Smokers and obese people have a higher risk of migraines. Lack of sleep, skipped meals and other factors can play a role. Sunlight flashing in a rearview mirror may set it off.

Foods are a common trigger, including MSG, sodium nitrates, cheese, chocolate, onions, citrus, peanut butter, red wine. Bauman says chocolate always set him up for debilitating migraines.

Baggaley sees a link between migraines and people who got carsick as kids.

Migraines typically start in childhood and may improve or get worse over the years. Migraines may last from a half hour to several hours. Some people suffer for days at a time. Frequency also varies. The headaches may plague someone only occasionally. Or they may be nearly daily visitors, the duration and severity variable. It's not uncommon for the headaches to trigger nausea and even vomiting. People with classic migraines may experience neurological effects, ranging from tingling to temporary partial paralysis or difficulty speaking.

Any migraine headache is generally made worse by noise, light or activity. That's why most migraineurs slug down some pain medicine and caffeine and head for dark, quiet places.