Causes and TriggersResearchers are unclear about the precise cause or causes of these headaches. There seems to be general agreement, however, that a key element is blood flow changes in the brain.
Other possible causes may include:
- Imbalances of brain chemicals
(Click Migraine Causes for more information.)
Also, while the direct cause is unknown, there are often controllable and uncontrollable migraine triggers. The most common ones are stress (see Stress-Related Migraines), anxiety, hormones, not eating, and weather changes. Certain types of food may also play a role (see Migraine Food Triggers or Migraine Diet).
Symptoms of a MigraineThe pain of a migraine headache is often described as an intense pulsing or throbbing pain in one area of the head. It is often accompanied by extreme sensitivity to light and sound, nausea and vomiting, or loss of appetite.
These symptoms are possible regardless of whether a person is experiencing classic or common migraines. However, a person with classic migraines also experiences an "aura" just before the headache begins. To simplify terminology, healthcare providers now refer to classic migraines as "migraines with aura" and common migraines as "migraines without aura."
Both classic and common symptoms can strike as often as several times a week or as rarely as once every few years. More than 50 percent of people experience no more than one headache per week. A migraine can occur any time of the day, though it often starts in the morning. The pain can last a few hours or up to one or two days.
(Click Migraine Symptoms to learn more about possible symptoms, including aura symptoms.)