Causes and Risks Headaches are a frequent cause of lost productivity and a common reason for seeking medical attention. Migraines are a common type of chronic headache, affecting about 6 out of 100 people. Migraines most commonly occur in women with onset between the ages of 10 and 46 years. They appear to run in families in some cases.
Classical migraine accounts for about one-sixth of all migraines.
The symptoms of migraine may occur as a result of changes in blood vessel diameter. Initially, constriction or spasm of blood vessels to the brain and surrounding structures may decrease blood flow to these areas. This can result in neurological symptoms other than headache, including visual changes, difficulty speaking, weakness or numbness of one part of the body, tingling sensations, and others. Classical migraine specifically refers to those migraines preceded by visual symptoms. Migraines have a multifactorial etiology.