Definition

A headache involves pain in the head which can arise
from many disorders or may be a disorder in and of itself.

Description

There are three types of primary headaches: tensiontype
(muscular contraction headache), migraine (vascular
headaches), and cluster. Virtually everyone experiences
a tension-type headache at some point. An estimated
18% of American women suffer migraines, compared
to 6% of men. Cluster headaches affect fewer than 0.5%
of the population, and men account for approximately
80% of all cases. Headaches caused by illness are secondary
headaches and are not included in these numbers.
Approximately 40