Hypertensive crisis in the critically ill.

Hypertensive crises encompass a spectrum of clinical presentations ranging from severe asymptomatic blood pressure (BP) elevation to life-threatening hypertensive emergencies and represent a frequent and challenging situation in the critically ill. While hypertensive urgency, defined as a marked elevation in blood pressure without acute organ damage, can generally be managed in the outpatient setting, hypertensive emergencies require immediate in-hospital management. Hypertensive emergencies are defined by a BP ≥180/110 mmHg associated with acute target-organ damage. Malignant hypertension represents a distinct and severe subset, further characterized by microvascular complications including hypertensive retinopathy and fibrinoid necrosis affecting multiple organs. Initial evaluation is critical to decipher between hypertensive urgency and emergency, with a systematic screening for end-organ damage: cardiovascular system (heart, aorta, and large vessels), central nervous system, retina, and kidneys. The acuity of BP rise, rather than its absolute level alone, largely determines the risk of organ injury, underscoring the importance of a thorough clinical and paraclinical assessment. Once a hypertensive emergency is identified, prompt initiation of intravenous antihypertensive therapy is mandatory. Drug selection, target BP, and the rate of BP reduction must be individualized according to the specific type of end-organ damage. In this narrative review, we summarize current definitions and epidemiology of hypertensive emergencies, detail the clinical approach to initial assessment, and provide an etiology-based overview of management strategies with a focus on intravenous antihypertensive agents and BP targets. Finally, we emphasize the importance of structured long-term follow-up after the acute phase, including etiological workup and optimization of antihypertensive therapy, to prevent recurrence and target-organ failure.