[Headache as an indicator of systemic disease].

Headaches can constitute a direct symptom and possibly the preliminary symptom of several autoimmune diseases and systemic vasculitis. In the majority of cases, the characteristics of the headache are not on their own sufficient to establish a certain diagnosis, which has to be based on the clinical context and on other migraine-associated signs. In practice, three main categories of headache can be indicative of systemic disease: craniofacial pain; migraine and pseudo-migraine; and headache caused by intracranial hypertension.