Migraine headaches are episodic, recurrent, throbbing headaches that usually occur on one side of the head. Migraines last from several hours to several days, and are often accompanied by nausea, vomiting and sensitivity to light and sound.
Types of Migraine
Migraines are classified into two types: classic or common. Classic migraine, or migraine with aura, is a migraine that is preceded by visual disturbances such as flashing lights, jagged lines or distorted images. There can also be neurological symptoms including numbness or weakness on one side of the body, severe dizziness or difficulty speaking. These pre-headache symptoms are the aura, which is an indication of the impending headache.
Common migraine is simply a migraine that sets in without an aura. However, many common migraine sufferers do notice subtle indications that a migraine is coming several hours or days before it starts. These symptoms include feeling elated, energetic, thirsty, hungry for sweets or feeling drowsy, irritable or depressed.
The exact cause of migraine headaches is unknown. Experts believe that migraines are hereditary, and that 60% of adults with migraines and 90% of children with migraines report a family history of the condition.
Several theories exist about their cause. Migraine pain is believed to be primarily related to abnormal constriction and dilation of blood vessels surrounding the brain. The reasons for these changes in blood vessels are unclear. One theory blames changes in the trigeminal nerve system—a major pathway in the brain—and another suggests that imbalances in the brain chemical serotonin might be the culprit.
A number of factors can generate migraines. Keep in mind that these triggers do not cause the pain associated with a migraine attack, but rather activate a chemical imbalance that already exists. Such triggers include: