Hypertension

Approach

Rule Out Hypertensive Emergency (End-Organ Damage)

Criteria: BP typically >180/120 mmHg PLUS acute, ongoing target organ damage.
Screen for Red Flags:
- Neurological: Severe headache, altered mental status, focal deficits, seizure (Hypertensive Encephalopathy, Stroke, Intracranial Hemorrhage).
- Cardiovascular: Severe chest pain, back pain radiating to shoulders/abdomen, dyspnea (Acute Coronary Syndrome, Aortic Dissection, Acute Pulmonary Edema).
- Renal: Oliguria, hematuria, acute elevation in serum creatinine (Acute Kidney Injury).
- Ocular: Papilledema, retinal hemorrhages, exudates (Fundoscopy).
- Obstetric: Pregnancy >20 weeks with BP >=140/90 mmHg plus proteinuria/end-organ features (Preeclampsia/Eclampsia).
Branching Logic:
- Presenting with End-Organ Damage: -> Hypertensive Emergency (Admit to ICU/HDU; IV antihypertensives; immediate controlled BP reduction).
- BP >180/120 mmHg WITHOUT End-Organ Damage: -> Severe Asymptomatic Hypertension (Formerly “Hypertensive Urgency”; rest in quiet room, recheck BP, adjust/restart oral meds, outpatient follow-up within 24–48 hours; avoid immediate IV drop).
- BP >=140/90 mmHg (or >=130/80 per ACC/AHA): -> Sustained Hypertension Workup (Outpatient confirmation via Ambulatory BP Monitoring [ABPM] or Home BP Monitoring [HBPM]).

The absolute level of blood pressure alone does NOT define a Hypertensive Emergency—the presence of acute end-organ damage does. Dropping BP too rapidly in severe asymptomatic hypertension can precipitate cerebral or myocardial ischemia.

Differential Diagnosis

Primary (Essential) Hypertension (>90% of cases):
- Distinguishing features: Gradual onset, typically age 30–50, positive family history, obesity, high sodium intake, sedentary lifestyle.
Secondary Hypertension (<10% of cases—suspect if age <30 or >55, sudden onset, drug-resistant [>=3 meds], or severe end-organ damage):
- Renal Parenchymal Disease (Most Common Secondary Cause):
  - Distinguishing features: History of CKD, elevated baseline creatinine, abnormal urinalysis (proteinuria, hematuria).
- Renovascular Hypertension (Renal Artery Stenosis):
  - Distinguishing features: Onset age <30 or >55, flash pulmonary edema, abdominal bruit, unexplained >=30% spike in creatinine after starting an ACEi/ARB.
- Primary Aldosteronism (Conn’s Syndrome):
  - Distinguishing features: Resistant hypertension, unexplained hypokalemia (though up to 50% are normokalemic), weakness, muscle cramps.
- Obstructive Sleep Apnea (OSA):
  - Distinguishing features: Habitual snoring, daytime somnolence, morning headaches, thick neck circumference.
- Pheochromocytoma:
  - Distinguishing features: Classic triad of paroxysmal Headache, Sweating (diaphoresis), and Tachycardia/Palpitations.
- Cushing’s Syndrome:
  - Distinguishing features: Moon facies, buffalo hump, central obesity, purple abdominal striae, proximal muscle weakness.
- Exogenous / Drug-Induced:
  - Distinguishing features: Use of NSAIDs, combined oral contraceptives, decongestants (pseudoephedrine), systemic steroids, cocaine, or excessive alcohol.

Think of the “Classic Secondary Clues”: Refractory BP on >=3 agents, acute worsening on ACEi/ARB (renal artery stenosis), or paroxysmal episodes of headache, sweating, and palpitations (pheochromocytoma).

Investigations

First-Line / Initial Diagnostic Workup (All Patients):

Confirmation: Outpatient 24-hour ABPM (Gold standard; average BP >=130/80 mmHg) or HBPM (average >=135/85 mmHg) to rule out White-Coat Hypertension.
Basic Labs:
- Serum Electrolytes & Creatinine/eGFR: Baseline renal function and potassium level.
- Fasting Blood Glucose / HbA1c: Screen for comorbid diabetes mellitus.
- Fasting Lipid Panel: Assess overall cardiovascular risk profile.
- Urinalysis & Urine Albumin-to-Creatinine Ratio (UACR): Detect subclinical renal end-organ damage or parenchymal disease.
12-Lead ECG: Assess for Left Ventricular Hypertrophy (LVH) or ischemic heart disease.

Targeted / Secondary Hypertension Workup (Indicated Cases):
- Primary Aldosteronism: Morning Plasma Aldosterone-to-Renin Ratio (ARR) (must hold spironolactone/eplerenone 4–6 weeks prior).
- Renal Artery Stenosis: Renal Duplex Ultrasound, CT Angiography, or MR Angiography.
- Pheochromocytoma: Plasma Free Metanephrines or 24-hour Urinary Fractionated Metanephrines.
- Cushing’s Syndrome: Overnight 1 mg Dexamethasone Suppression Test or 24-hour Urinary Free Cortisol.
- Obstructive Sleep Apnea: Polysomnography (Sleep Study).

Always obtain a baseline ECG and urine protein/creatinine ratio at initial diagnosis. Subclinical Left Ventricular Hypertrophy or microalbuminuria alters risk stratification and guides drug selection (e.g., prioritizing ACEi/ARBs).

Critical Management

Hypertensive Emergency (Admit to ICU):
- Target: Lower Mean Arterial Pressure (MAP) by <=25% within the first hour, then down to 160/100 mmHg over the next 2–6 hours, then normalize over 24–48 hours using IV infusions (e.g., Labetalol, Nicardipine, Sodium Nitroprusside).
- CRITICAL EXCEPTIONS to the gradual lowering rule:
  - Acute Aortic Dissection: Rapidly lower Systolic BP to <120 mmHg and Heart Rate to <60 bpm within 20 minutes (typically IV Esmolol + Vasodilator).
  - Acute Ischemic Stroke: Do NOT lower BP unless >=220/120 mmHg (or >=185/110 mmHg if candidate for thrombolysis/tPA).

In acute aortic dissection, target a Systolic BP <120 mmHg within minutes. In acute ischemic stroke, permit hypertension to maintain cerebral perfusion pressure—do not treat unless BP exceeds 220/120 mmHg (or 185/110 mmHg before tPA).

References

European Society of Cardiology. 2024 ESC guidelines for the management of elevated blood pressure and hypertension [Internet]. 2024 [corrected 2025; cited 2026 Aug 20]. Available from: https://www.escardio.org/guidelines/clinical-practice-guidelines/all-esc-practice-guidelines/elevated-blood-pressure-and-hypertension/
National Institute for Health and Care Excellence. Hypertension in adults: diagnosis and management (NG136) [Internet]. 2019 [updated 2023; cited 2026 Aug 20]. Available from: https://www.nice.org.uk/guidance/ng136