Throughout history, physicians have approached a disease by recognizing it as an entity, understanding its nature, and searching for its cause. They have devised treatments that flow logically from that understanding. Headache, an ancient and much-studied complaint, has a rich historical literature that illustrates the evolution of our knowledge from the magical to the molecular level.
Five thousand years ago, Mesopotamian physicians viewed headache as a disease entity rather than a symptom and attributed it to an evil spirit named Tiu. A clinical description from that time noted: