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One of the causes of migraines is changes in the level of a chemical called serotonin that the brain produces, and this can have an effect on blood vessels.
When serotonin levels are elevated, blood vessels become narrow, while when levels are lower, the blood vessels dilate, i.e. they swell. The swelling can cause pain or other problems. Serotonin levels can change depending on the level of blood sugar, certain foods and changes in the level of oestrogen in the case of women.
Another possible cause of migraine relates to genes that control the activity of some brain cells.
Treatment. Drugs to treat painful episodes and to reduce the frequency with which they occur.
