Eyestrain and other eye problems. Problems of the ear and inner ear. Nerve pressure or traction on a nerve or nerves in the neck. Contraction or dilation of blood vessels in the head. Cluster headaches, very common and can be related to stress, and histamine release.
Migraine headaches are one of the more severe headache types and can be very debilitating in nature.
There is no known cause, however, it is generally thought that it is due to constriction or dilation of blood vessels in the circulation of the head. Flashes of light, changes in eyesight and some numbness and tingling often precede migraine. Pain usually occurs one side of the head, but at times may be generalized. Migraines can occur on a daily basis or once in several months, and can last for hours or days. Intolerance to light, nausea and vomiting and no appetite usually accompany them.