INTRODUCTION AND DEFINITION
Severe hypertension in adults (often defined as systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥120 mmHg) can be associated with a variety of acute, life-threatening complications, any one of which is considered a hypertensive emergency . These include hypertensive encephalopathy, retinal hemorrhages, papilledema, or acute and subacute kidney injury (table 1). A review of the manifestations and treatment of hypertensive emergencies is discussed separately. (See "Moderate to severe hypertensive retinopathy and hypertensive encephalopathy in adults".)
Much more common, however, is the relatively asymptomatic patient with a blood pressure in the "severe" range (ie, ≥180/≥110 mmHg), often a mild headache, but no signs or symptoms of acute end-organ damage. This entity of severe asymptomatic hypertension is called hypertensive urgency and, as with hypertensive emergencies, occurs more frequently among patients who have been nonadherent with either their chronic antihypertensive drug regimen or their low-sodium diet . Severe hypertension can also develop in medication-adherent patients following ingestion of large quantities of salt  and can be controlled by resuming a low-salt diet . (See "Initial evaluation of the hypertensive adult" and "Overview of hypertension in acute and chronic kidney disease".)
This topic reviews the treatment of severe asymptomatic hypertension, or hypertensive urgency. The recommendations below apply only to patients without signs of acute or ongoing end-organ damage.
The evaluation of patients with hypertension, the treatment of hypertensive emergencies, and the treatment of the pregnant woman with severe hypertension are discussed separately. (See "Initial evaluation of the hypertensive adult" and "Moderate to severe hypertensive retinopathy and hypertensive encephalopathy in adults" and "Evaluation and treatment of hypertensive emergencies in adults" and "Management of hypertension in pregnant and postpartum women" and "Expectant management of severe preeclampsia".)
The most important aspect of the initial assessment of the patient with severely elevated blood pressure is to exclude acute, ongoing, target-organ damage, which would indicate a diagnosis of hypertensive emergency rather than severe asymptomatic hypertension. (See "Evaluation and treatment of hypertensive emergencies in adults".)