1. Introduction
Hypertension (HTN) is a chronic elevation of blood pressure (BP) and a leading risk factor for cardiovascular disease (CVD), stroke, renal failure, and heart failure. It is often asymptomatic, earning it the name “silent killer.” Early detection and effective management significantly reduce morbidity and mortality.
2. Definition and Classification of Hypertension
Blood pressure is measured in millimeters of mercury (mmHg) and classified according to NICE and European Society of Cardiology (ESC) guidelines.
(A) Blood Pressure Categories
| Category | Systolic BP (mmHg) | Diastolic BP (mmHg) |
|---|---|---|
| Normal BP | <120 | <80 |
| Elevated BP (Prehypertension) | 120-129 | <80 |
| Hypertension Stage 1 | 130-139 | 80-89 |
| Hypertension Stage 2 | 140-179 | 90-119 |
| Hypertensive Crisis (Emergency) | ≥180 | ≥120 |
🔹 Ambulatory Blood Pressure Monitoring (ABPM) and Home BP Monitoring (HBPM) are recommended for confirming a diagnosis.
3. Pathophysiology of Hypertension
Hypertension is either primary (essential, 90-95%) or secondary (5-10%).
(A) Primary Hypertension (90-95%)
- No identifiable cause
- Risk factors: Age, obesity, high salt intake, genetics, smoking, sedentary lifestyle, stress
(B) Secondary Hypertension (5-10%)
- Renal causes: Chronic kidney disease (CKD), renal artery stenosis
- Endocrine causes: Cushing’s syndrome, pheochromocytoma, hyperaldosteronism
- Vascular causes: Coarctation of the aorta
- Drug-induced: NSAIDs, steroids, cocaine, oral contraceptives
4. Diagnosis of Hypertension
(A) Clinical Evaluation
- Confirming BP readings
- BP should be measured on 2 different occasions at least 1 week apart.
- ABPM/HBPM should be considered if clinic BP is elevated.
- History and Risk Assessment
- Symptoms (headache, dizziness, vision changes)
- Cardiovascular risk factors (smoking, diabetes, dyslipidemia, obesity)
- Family history of hypertension or cardiovascular disease
- Physical Examination
- BP measurement in both arms
- Fundoscopy (hypertensive retinopathy)
- Signs of secondary hypertension (renal bruits, Cushing’s features, thyroid abnormalities)
(B) Laboratory and Imaging Workup
| Investigation | Purpose |
|---|---|
| Urinalysis & ACR | Proteinuria (hypertensive nephropathy) |
| Serum Electrolytes & Renal Function | Assess kidney function, hyperaldosteronism |
| Lipid Profile | Assess CVD risk |
| HbA1c/Fasting Glucose | Detect diabetes |
| ECG | Look for LV hypertrophy, ischemia |
| Echocardiography | Evaluate left ventricular hypertrophy |
| Renal Ultrasound & Doppler | Detect renal artery stenosis |
5. Hypertension Management Protocol
(A) Non-Pharmacological Management (Lifestyle Modifications)
Recommended for all patients, even those on medication.
| Lifestyle Change | Effect on BP |
|---|---|
| Salt restriction (<2g/day) | ↓ 5-6 mmHg |
| Weight loss (BMI <25 kg/m²) | ↓ 5-10 mmHg |
| Regular exercise (30 min/day, 5 days/week) | ↓ 4-9 mmHg |
| DASH diet (high in fruit, veg, low-fat dairy) | ↓ 8-14 mmHg |
| Alcohol moderation (<14 units/week) | ↓ 2-4 mmHg |
| Smoking cessation | Reduces cardiovascular risk |
(B) Pharmacological Management
Initiated if:
- Stage 1 HTN + End-organ damage or high CVD risk
- Stage 2 HTN (≥140/90 mmHg)
- Diabetes with BP ≥130/80 mmHg
Stepwise Drug Therapy (NICE Guidelines)
| Step | Age <55 or Diabetes | Age >55 or Black ethnicity |
|---|---|---|
| Step 1 | ACE inhibitor (e.g., Ramipril) | Calcium channel blocker (e.g., Amlodipine) |
| Step 2 | ACE inhibitor + CCB | CCB + Thiazide diuretic |
| Step 3 | ACE inhibitor + CCB + Thiazide | |
| Step 4 (Resistant HTN) | Add Spironolactone if K+ <4.5 or β-blocker if K+ >4.5 |
(C) Special Situations
- Hypertensive Emergency (BP ≥180/120 mmHg + Organ Damage)
- Requires immediate IV antihypertensives (labetalol, nitroprusside)
- Reduce BP by ≤25% in first hour to prevent ischemia
- Hypertensive Urgency (BP ≥180/120 mmHg, No Organ Damage)
- Gradual BP reduction over 24-48 hours with oral antihypertensives
- Hypertension in Pregnancy
- First-line: Labetalol, nifedipine, methyldopa
- Avoid: ACE inhibitors and ARBs (teratogenic)
- Secondary Hypertension
- Hyperaldosteronism → Spironolactone
- Pheochromocytoma → α-blockers before β-blockers
6. Complications of Uncontrolled Hypertension
🚨 Cardiovascular Complications
- Stroke (ischemic/hemorrhagic)
- Myocardial infarction (MI)
- Heart failure (left ventricular hypertrophy, cardiomyopathy)
- Aneurysms (aortic dissection, ruptured aneurysms)
🚨 Renal Complications
- Hypertensive nephropathy → CKD → Dialysis
- Proteinuria due to glomerular damage
🚨 Ophthalmic Complications
- Hypertensive retinopathy (Grade 1-4, flame hemorrhages, papilledema)
- Blindness from optic neuropathy
🚨 Neurological Complications
- Vascular dementia (chronic cerebral hypoperfusion)
7. Key Takeaways
✅ Hypertension is a major risk factor for stroke, MI, and CKD – early detection is crucial
✅ Diagnosis is based on persistent BP elevation confirmed by ambulatory/home monitoring
✅ Lifestyle modifications are recommended for all patients
✅ First-line drugs vary by age and ethnicity (ACEi for younger, CCB for older/Black patients)
✅ Uncontrolled HTN leads to stroke, heart failure, kidney failure, and blindness
Further Reading
