Dictionary.net

Pain in the cranial region that may occur as an isolated and benign symptom or as a manifestation of a wide variety of conditions including SUBARACHNOID HEMORRHAGE; CRANIOCEREBRAL TRAUMA; CENTRAL NERVOUS SYSTEM INFECTIONS; INTRACRANIAL HYPERTENSION; and other disorders. In general, recurrent headaches that are not associated with a primary disease process are referred to as HEADACHE DISORDERS (e.g., MIGRAINE).