The term hypertensive encephalopathy should be reserved for patients with diffuse cerebral effects of precipitous and sustained rises in blood pressure that reverse when blood pressure is lowered and are not due to infarction or hemorrhage. The definitive diagnosis of this syndrome depends on accurate exclusion of other causes that may be associated with elevated blood pressure and neurologic deficits. Treatment is aimed at preventing or limiting target organ (brain) damage. Therapy should be individualized but centered on reducing the mean arterial blood pressure within a period of minutes to 2 hours, by no more than 20% to 25% or to a diastolic blood pressure of 100 to 110 mm Hg (whichever is higher), using short-acting intravenous agents. Oral or sublingual agents should generally be avoided in hypertensive encephalopathy because they are more likely to cause precipitous falls in blood pressure.