When is a headache more than just a headache?

In Canadian Medical Association Journal are two studies on migraine management. Migraine is quite common with some 8% of men and 18% of women experiencing migraines. Headaches are typically primary headaches meaning there is no underlying cause such as a tumor, injury, or an aneurysm. Of the common primary headaches, they can be tension headaches, cluster headaches, and migraines.