Diagnosing the severe headache.

A patient's medical history, age of onset, location of pain, pain characteristics, pain chronology, associated signs and symptoms, and signs of neurologic dysfunction are all important considerations in making a diagnosis. The International Headache Society has developed a thorough classification system to aid in the diagnosis of headache, which includes primary disorders of migraine, tension-type headache, and cluster headache, as well as secondary, organic disorders.