Severe and rapidly rising blood pressure that can irreversibly damage the cardiovascular, renal, and nervous systems. Blood pressure over 180 (systolic) or 120 (diastolic), and sometimes lower, is considered a hypertensive emergency requiring immediate care. Other findings include headache, papilledema, impaired renal function, retinal hemorrhage, hypertensive encephalopathy, and microscopic hematuria. Less common in Western countries where antihypertensive medications are more commonly in use, it is mostly seen in underdeveloped nations and among immigrants.

Management requires appropriate response to hypertensive emergency, avoiding a too-rapid lowering of blood pressure. Treatments also depend on the extent and location of organ damage and presenting symptoms. Left untreated, prognosis is poor.