What is the difference between hypertensive urgency and hypertensive emergency?

Hypertensive Urgency vs. Emergency: The Critical Distinction

The presence or absence of acute target organ damage is the sole deciding factor—not the blood pressure number itself—that distinguishes hypertensive emergency from urgency. 1, 2

Key Definitions

Hypertensive Emergency

• Severely elevated BP (>180/120 mmHg) WITH evidence of new or progressive acute target organ damage 1, 2
• Requires immediate intervention in an ICU setting with IV medications 1, 3
• Carries a 1-year mortality rate >79% if untreated 1, 2
• The rate of BP rise may be more important than the absolute number—patients with chronic hypertension often tolerate higher pressures than previously normotensive individuals 1

Hypertensive Urgency

• Severely elevated BP (>180/120 mmHg) WITHOUT acute target organ damage 1, 2
• Patients are clinically stable with no evidence of acute end-organ dysfunction 2
• Can be managed with oral medications and outpatient follow-up—no ICU admission or IV therapy required 1, 2
• This is essentially a diagnosis of exclusion 4

Identifying Target Organ Damage: The Critical Assessment

You must systematically evaluate for acute damage in these organ systems: 1, 3

Neurologic Damage

• Hypertensive encephalopathy: seizures, lethargy, cortical blindness, coma, altered mental status 4, 1
• Acute ischemic stroke 4, 1
• Intracranial hemorrhage 4, 1

Cardiac Damage

• Acute myocardial infarction or unstable angina 1, 3
• Acute left ventricular failure with pulmonary edema 1, 3
• Acute coronary syndrome 4, 1

Ophthalmologic Damage

• Malignant hypertension: bilateral flame-shaped hemorrhages, cotton wool spots, or papilledema (Grade III-IV retinopathy) 4, 3
• Note that advanced retinopathy may be lacking in up to one-third of patients with hypertensive encephalopathy 4

Renal Damage

• Acute kidney injury 1, 3
• Thrombotic microangiopathy (TMA): Coombs-negative hemolysis with elevated LDH, unmeasurable haptoglobin, schistocytes, and thrombocytopenia 4, 1

Vascular Damage

• Acute aortic dissection or aneurysm 4, 1, 3

Obstetric

• Severe preeclampsia or eclampsia 4, 1

Management Implications: Why This Distinction Matters

For Hypertensive Emergency

Admit to ICU immediately with continuous arterial BP monitoring and IV titratable agents 1, 3, 2

Target BP reduction: 1, 2

• Reduce mean arterial pressure by no more than 25% within the first hour
• Then reduce to 160/100-110 mmHg over the next 2-6 hours if stable
• Cautiously normalize BP over 24-48 hours

Exception—more aggressive targets for: 1, 2

• Aortic dissection: SBP <120 mmHg immediately
• Severe preeclampsia/eclampsia: SBP <160 mmHg immediately
• Acute pulmonary edema: SBP <140 mmHg immediately

First-line IV medications: 1, 3

• Nicardipine: 5 mg/hr IV, titrate by 2.5 mg/hr every 5-15 minutes (max 15 mg/hr)
• Labetalol: 0.3-1.0 mg/kg slow IV every 10 minutes or 0.4-1.0 mg/kg/hr infusion

For Hypertensive Urgency

Reinstitute or intensify oral antihypertensive therapy—no ED referral or hospitalization needed 1, 2

• Start or restart long-acting oral agents: combination of ACE inhibitor/ARB, thiazide diuretic, and/or calcium channel blocker 5
• Arrange outpatient follow-up within 2-4 weeks 1
• Target BP <130/80 to <140/90 mmHg depending on patient characteristics 1

Critical Pitfalls to Avoid

Do not treat the BP number alone without assessing for true target organ damage 1—many patients with acute pain or distress have transiently elevated BP that normalizes when the underlying condition is treated 1

Avoid excessive acute BP drops (>70 mmHg systolic) 1, 3—this can precipitate cerebral, renal, or coronary ischemia, especially in patients with chronic hypertension who have altered autoregulation 4, 1

Never use immediate-release nifedipine 1, 3—it causes unpredictable precipitous BP drops and reflex tachycardia that can worsen myocardial ischemia 1

Do not aggressively treat hypertensive urgency with IV medications 3, 2—up to one-third of patients with diastolic BP >95 mmHg normalize before follow-up, and rapid BP lowering may be harmful 1

Remember that patients with chronic hypertension cannot tolerate acute normalization of BP 1, 3—their cerebral autoregulation is shifted rightward, making them vulnerable to ischemia at "normal" pressures 4, 1