What Causes Migraine and Cluster Headaches?
Many experts believe that migraine and cluster headaches share a common cause that begins in the nerve that carries sensation from the head to the brain (trigeminal nerve). Blood vessels on the brain’s surface expand (dilate), causing swelling in an area and pressure on nerve endings. The nerve endings submit signals to the brain to perceive pain. This may also explain some other symptoms associated with migraines, such as nausea, vomiting, and visual disturbances.