Migraine and tension-type headaches: the questionable validity of current classification systems.

Headache is the most common symptom patients present to their doctors. Current systems classify the most common recurring headaches as either migraine or tension-type. Review of the literature brings into question this traditional approach to headache classification. These two "types" of headache patterns appear, instead, to be different expressions of the same pathophysiological process, having overlapping symptomatic presentations with certain features emphasized to a greater or lesser extent. Additionally, the same therapies have been demonstrated to be effective for patients traditionally classified in either headache group. This article reviews the overlap of clinical symptoms, pathophysiology, and effective treatments for headaches traditionally diagnosed as migraine and tension-type. An alternative continuum classification model is suggested.