Causes of Headache

Types and Causes of Headaches

Headache is divided into two basic types: primary and secondary.

Secondary headaches are those that are due to some underlying cause, like a sinus or brain infection, head or neck injury, or a brain tumor. Most headaches that occur are not due to any kind of secondary cause, and are what we call primary headaches. Less than 5% of all headaches are secondary headaches. Although infrequent, there are over a hundred types of secondary headache, which is why there are expert headache doctors.

Primary headaches are those that do not have any sort of underlying cause. The most commonly occurring primary headache is tension-type headache. Migraine, also a primary headache, affects about 6% of men in the population, and 18-20% of women, depending on what country you live in. Cluster headache, a primary headache in the group of headaches known as the trigeminal autonomic cephalgias, is far less common. So what causes migraine? In most cases, they are thought to be genetic. Triggers set off a migraine attack, but are not the cause of the underlying migraine disorder. The biochemical and physiologic basis of migraine is called pathophysiology, and is quite complex. We are still figuring out all the things that occur in the brain when a migraine happens.

by Christina Peterson, M.D.

updated Feb 8, 2010