When should a patient with hypertension be sent to the emergency room (ER)?

When to Send a Patient to the ER for Hypertension

Send a patient to the emergency room immediately when blood pressure exceeds 180/120 mmHg AND there is evidence of acute target organ damage—this defines a hypertensive emergency requiring ICU admission and IV therapy. 1, 2

Critical Distinction: Emergency vs. Urgency

The presence or absence of acute target organ damage—not the absolute blood pressure number—determines whether ER referral is necessary. 1, 2

Hypertensive Emergency (Requires Immediate ER Transfer)

Blood pressure >180/120 mmHg WITH any of the following acute organ damage: 3, 1

Neurologic:

• Hypertensive encephalopathy (altered mental status, seizures, cortical blindness, coma) 3
• Acute ischemic stroke 3
• Intracranial hemorrhage 3
• Severe headache with visual disturbances suggesting acute brain injury 1

Cardiac:

• Acute myocardial infarction or unstable angina 1, 2
• Acute left ventricular failure with pulmonary edema 3, 1
• Cardiogenic pulmonary edema (sudden dyspnea with hypertension) 1

Vascular:

• Aortic dissection or aneurysm 3, 1

Renal:

• Acute kidney injury 1
• Hypertensive thrombotic microangiopathy (hemolysis with thrombocytopenia) 3

Ophthalmologic:

• Malignant hypertension with advanced retinopathy (hemorrhages, cotton wool spots, papilledema on fundoscopy) 3, 1

Obstetric:

• Severe preeclampsia or eclampsia 3, 1

Hypertensive Urgency (Does NOT Require ER)

Blood pressure >180/120 mmHg WITHOUT acute target organ damage can be managed with oral medications and outpatient follow-up within one week. 2, 4 These patients do not require hospital admission or IV medications. 1

Key Clinical Pearls

The rate of blood pressure rise may be more important than the absolute number—patients with chronic hypertension often tolerate higher pressures than previously normotensive individuals. 1 However, this does not change the threshold for ER referral when organ damage is present.

Without treatment, hypertensive emergencies carry a 1-year mortality rate >79% and median survival of only 10.4 months. 1 This underscores the critical importance of immediate recognition and transfer.

Common Pitfalls to Avoid

Do not send asymptomatic patients with severely elevated blood pressure to the ER without evidence of organ damage. Up to one-third of patients with diastolic BP >95 mmHg normalize before follow-up, and rapid BP lowering may be harmful. 1 The short-term risk of acute target organ injury is low without symptoms. 2

Do not be falsely reassured by patients who "feel fine." Perform a focused assessment for subtle signs of organ damage: 3, 1

• Brief neurologic exam (mental status, visual changes, focal deficits)
• Cardiac assessment (chest pain, dyspnea, signs of heart failure)
• Fundoscopic exam if available (papilledema, hemorrhages)
• Urinalysis for proteinuria or hematuria

Many patients with acute pain or distress have transiently elevated BP that normalizes when the underlying condition is treated—avoid treating the BP number alone without assessing for true hypertensive emergency. 1

Special Populations Requiring Lower Threshold for ER Referral

Patients with the following characteristics have higher risk of end-organ damage and warrant more aggressive screening: 5

• Age >60 years
• History of diabetes mellitus
• History of ischemic heart disease
• History of cerebrovascular accident

In these high-risk patients, consider ER referral even with borderline symptoms or equivocal findings, as they have 8.3% prevalence of new-onset end-organ damage. 5

Practical Assessment Algorithm

Step 1: Confirm BP >180/120 mmHg with repeat measurement 3

Step 2: Assess for symptoms suggesting organ damage: 3, 1

• Headache, visual changes, altered mental status, seizures (neurologic)
• Chest pain, dyspnea (cardiac)
• Severe back/chest pain (vascular)
• Decreased urine output (renal)

Step 3: If ANY symptoms present → Send to ER immediately 1, 2

Step 4: If asymptomatic, perform focused exam: 3, 1

• Neurologic exam
• Cardiac exam
• Fundoscopy if trained
• Urinalysis if available

Step 5: If exam reveals organ damage → Send to ER immediately 1, 2

Step 6: If truly asymptomatic with normal exam → Initiate/adjust oral antihypertensives and arrange follow-up within one week 2, 4