The most common theory about migraine headaches is that various triggers cause abnormal brain activity, which in turn causes changes in the blood vessels in the brain. This is called the neuro-vascular theory.
Genetics also plays a role in migraines and there are some forms of migraines that are associated with inherited abnormalities in certain parts of the brain.
Migraine headache pain is often at times moderate to severe and is usually described as a pounding or throbbing pain. Migraines can last from four hours to three days and usually occur one to four times per month.
Migraines are associated with symptoms such as sensitivity to light, noise, or odors; nausea or vomiting; loss of appetite; and stomach upset or abdominal pain.