5. Hypertensive Emergency

📄 Definition

A hypertensive emergency is a severe elevation in blood pressure (usually systolic BP ≥180 mmHg and/or diastolic BP ≥110 mmHg) with acute target organ damage.

Contrast with:

  • Hypertensive urgency: severely elevated BP without target o

🛡️ Causes

  • Essential hypertension (poorly controlled)

  • Renal disease (e.g. glomerulonephritis, renal artery stenosis)

  • Phaeochromocytoma

  • Pre-eclampsia/eclampsia

  • Drugs: cocaine, amphetamines, MAOIs

  • Rebound hypertension (e.g. clonidine withdrawal)

⚠️ Common Acute Complications

CRISIS TARGETS 

  • CHF (acute heart failure)

  • Retinal haemorrhages/papilloedema

  • Ischemic stroke

  • Subarachnoid haemorrhage

  • Ischemic heart disease (MI/angina)

  • Scanning signs (CT/MRI abnormalities)

  • TIA

  • AKI (renal impairment)

  • Reflex encephalopathy

  • Gross haematuria

  • Eclampsia

  • Thrombotic microangiopathy

  • Seizures

📋Clinical features of End-Organ Damage

  • Neurological: headache, confusion, seizures, visual disturbance

  • Cardiac: chest pain, dyspnoea, palpitations

  • Renal: oliguria, haematuria

  • Ophthalmic: blurred vision, papilloedema

🔬 Diagnosis

  • BP measurement in both arms

  • Fundoscopy: retinal changes (Grade III/IV hypertensive retinopathy)

  • Urinalysis: haematuria, proteinuria

  • ECG: LVH, MI changes

  • Bloods: U&Es, FBC, LFTs, Troponin, TFTs

  • Imaging:

    • CXR (pulmonary oedema)

    • CT head (if neuro signs)

    • Echo if cardiac involvement

❗ Complications

  • Stroke

  • Myocardial infarction

  • Aortic dissection

  • Pulmonary oedema

  • Encephalopathy

  • Acute kidney injury

  • Death

🧐 Differentials

  • Anxiety or pain-induced BP rise (transient)

  • Essential hypertension

  • Hypertensive urgency (no organ damage)

  • Cushing’s, Conn’s syndrome, phaeochromocytoma

Last updated in line with NICE NG136 (Hypertension in adults): March 2022
Last reviewed: July 2025
PASSMAP ensures all content is NICE-aligned and reviewed for Physician Associate Registration Assessment (PARA) success.

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