What is a migraine headache?
A migraine is usually an intense pounding headache with nausea that occurs from time to time. The pounding or pulsing pain usually begins in the forehead, the side of the head or around the eyes. The headache gradually gets worse. Just about any movement or activity seems to make it hurt more. Nausea and vomiting are common. Bright lights or loud noises make the headache worse. The headache can last for two hours or even up to two or three days. Some people see a pattern of lines or shadows in front of their eyes as the headache is beginning. This is called a “warning aura.” Most people with migraine do not have this.
A migraine headache is a form of vascular headache. Migraine headache is caused by a combination of vasodilatation (enlargement of blood vessels) and the release of chemicals from nerve fibers that coil around the blood vessels. During a migraine attack, the temporal artery enlarges. (The temporal artery is an artery that lies on the outside of the skull just under the skin of the temple.) Enlargement of the temporal artery stretches the nerves that coil around the artery and causes the nerves to release chemicals. The chemicals cause inflammation, pain, and further enlargement of the artery. The increasing enlargement of the artery magnifies the pain. Migraine attacks commonly activate the sympathetic nervous system in the body. The sympathetic nervous system is often thought of as the part of the nervous system that controls primitive responses to stress and pain, the so-called “fight or flight” response. The increased sympathetic nervous activity in the intestine causes nausea, vomi
Recent scientific evidence suggests that migraine headaches begin with a release of proteins by nerve endings in the fibrous outer covering of the brain (called the dura mater) resulting in the dilation of the cranial blood vessels following an initial contraction. During a migraine, inflammation of the tissue surrounding the brain exacerbates the pain. Unlike most other types of headache, migraines may have many additional symptoms. Migraines are sometimes preceded by visual auras. Following the onset of a migraine attack, symptoms may include throbbing, nausea, sensitivity to light and/or sound, difficulty in speech and semi-hemispheric head pain. A migraine attack can last for hours or days. Approximately 75% of migraine sufferers are female and both the etiology and incidence of migraine attacks vary with the individual.
