Acute and chronic hypertensive headache and hypertensive encephalopathy.

Three patients are described who experienced headache from hypertension: one had acute headache from acute hypertension, one had daily, morning headaches from chronic hypertension, and one had acute headache with generalized tonic-clonic seizure from hypertensive encephalopathy. The presumed pathophysiological mechanisms involved in the three hypertensive headache conditions are reviewed.