A hypertensive emergency is a rare event in which an acute elevation of blood pressure causes rapid progressive end-organ damage. Cardiovascular, renal and central nervous system syndromes may be associated with acute blood pressure elevations. Prompt treatment with antihypertensive agents should be initiated while the patient is closely monitored. Lowering the blood pressure too quickly can exacerbate symptoms and decrease organ blood flow. Treatment must be individualized depending on the end organ involved and the patient's clinical status. A general goal is to lower the mean arterial pressure by approximately 20 to 25 percent or reduce the diastolic pressure to 100 to 110 mm Hg over a one-hour period. Medications such as nitroprusside allow minute-to-minute regulation of the patient's blood pressure and clinical symptoms.