Related Subjects:
|Assessing Chest Pain
|Hypertension
|Hypertension in Pregnancy
|Malignant Hypertension
|Preeclampsia, Eclampsia and HELLP
|Acute Heart Failure
|Chronic Heart Failure
|Essential Hypertension
Hypertension is defined as a persistent elevation in blood pressure,
with clinic BP ≥140/90 mmHg, confirmed using ABPM or HBPM ≥135/85 mmHg.
📊 Diagnosis should always be confirmed with out-of-office readings to exclude white-coat hypertension.
👉 Stage 1 HTN: 140–159 / 90–99 mmHg
👉 Stage 2 HTN: ≥160 / 100 mmHg
👉 Severe HTN: ≥180 / 120 mmHg (urgent assessment required 🚨)
💡 Around 90–95% is essential hypertension; secondary causes (5–10%) must be actively considered in appropriate patients.
🧠 Pathophysiology (Why BP Causes Damage)
- 🧬 Chronic ↑ systemic vascular resistance → endothelial dysfunction & nitric oxide depletion
- 🫀 Pressure overload → left ventricular hypertrophy → diastolic dysfunction → HFpEF
- 🧠 Lipohyalinosis of small vessels → lacunar stroke & vascular dementia
- 🧪 Glomerular hypertension → proteinuria & CKD progression
- ⚡ Accelerated atherosclerosis → MI, PAD
Teaching point: Hypertension is best understood as a chronic vascular injury syndrome, not just a number.
⚠️ Who to Treat (NICE NG136)
- 🔴 Stage 2 HTN: Treat all patients
- 🟡 Stage 1 HTN: Treat if:
- 🧠 Target organ damage (LVH, CKD, retinopathy)
- 💔 Established cardiovascular disease
- 🧪 Diabetes
- 📊 QRISK ≥10%
- 👤 Age <80 years
- 👵 ≥80 years → individualised decision (consider frailty, falls risk)
🎯 Blood Pressure Targets (NICE)
| Group |
Clinic Target |
ABPM/HBPM Target |
| 🧑 <80 years |
<140/90 mmHg |
<135/85 mmHg |
| 👵 ≥80 years |
<150/90 mmHg |
<145/85 mmHg |
⚠️ NICE does not mandate lower targets purely for diabetes or CKD, unlike some international guidelines.
⚠️ Risk Factors for Essential Hypertension
- 🌍 Ethnicity (higher prevalence in Black populations)
- 🧬 Genetic predisposition
- 🧂 High salt intake → volume expansion
- ⚖️ Obesity → RAAS activation + insulin resistance
- 🍷 Excess alcohol
- 🛌 Poor sleep (e.g. OSA → sympathetic overactivity)
🔎 Clinical Clues to Secondary Hypertension
- 🦵 Radio–femoral delay → coarctation of aorta
- 🎧 Renal bruit → renal artery stenosis
- 😰 Episodic headache + sweating → phaeochromocytoma
- 🧂 Hypokalaemia → primary hyperaldosteronism
- 🫣 Resistant HTN (≥3 drugs) → secondary cause likely
- 💊 Drugs: NSAIDs, steroids, COCP, sympathomimetics
🧪 Baseline Investigations (NICE)
- 🩸 Lipids + HbA1c → CV risk
- 🧪 U&E, eGFR → renal function
- 🧾 Urine ACR → proteinuria
- 📈 ECG → LVH, AF
- 🫀 Echo if clinically indicated
📑 Stepwise Pharmacological Treatment (ABCD Algorithm)
| Step |
Recommendation |
| 1️⃣ |
A (ACEi/ARB) if <55 years OR diabetes
C (CCB) if ≥55 years or Black ethnicity
|
| 2️⃣ |
A + C |
| 3️⃣ |
A + C + D (thiazide-like diuretic, e.g. indapamide) |
| 4️⃣ |
Resistant HTN:
• Add spironolactone if K⁺ ≤4.5 mmol/L
• Otherwise consider α-blocker or β-blocker
• Seek specialist advice
|
💡 Avoid ACEi + ARB combination (no added benefit, ↑ harm).
💊 Drug Class Insights (Clinical Reasoning)
- 🧬 ACEi/ARB: RAAS blockade → best for CKD, diabetes, younger patients
- 💊 CCB: vasodilation → particularly effective in elderly/Black patients
- 🧪 Thiazides: volume reduction → useful in salt-sensitive HTN
- 💊 Beta-blockers: not first-line unless compelling indication (e.g. IHD, AF, HF)
💊 Typical Antihypertensive Drug Titration Examples (NICE NG136)
🧬 ACE Inhibitor (e.g. Ramipril)
| Step | Dose | Notes |
|---|
| Start | 2.5 mg OD | Lower (1.25 mg) if elderly/frail or CKD |
| 2–4 weeks | 5 mg OD | Check U&E before up-titration |
| Target | 10 mg OD | Maximal BP effect usually here |
- 🧪 Check U&E and K⁺ at baseline and after each dose increase
- ⚠️ Acceptable: creatinine rise ≤30%
- ❌ Avoid in bilateral renal artery stenosis, pregnancy
💊 ARB (e.g. Losartan)
| Step | Dose | Notes |
|---|
| Start | 50 mg OD | Use if ACEi not tolerated (e.g. cough) |
| 2–4 weeks | 100 mg OD | Typical max dose |
- 🧪 Same monitoring as ACEi (K⁺, creatinine)
- 💡 No added benefit combining ACEi + ARB ❌
💊 Calcium Channel Blocker (e.g. Amlodipine)
| Step | Dose | Notes |
|---|
| Start | 5 mg OD | First-line in ≥55 or Black ethnicity |
| 2–4 weeks | 10 mg OD | Max dose |
- ⚠️ Common: ankle oedema, flushing, headache
- 💡 If oedema problematic → add ACEi rather than stop
🧪 Thiazide-like Diuretic (e.g. Indapamide)
| Formulation | Dose | Notes |
|---|
| Modified release | 1.5 mg OD | Preferred option |
| Standard | 2.5 mg OD | Alternative |
- 🧪 Monitor Na⁺, K⁺, renal function
- ⚠️ Risk: hyponatraemia, hypokalaemia, gout
💊 Step 4 (Resistant Hypertension)
| Drug | Dose | When to Use |
|---|
| Spironolactone |
25 mg → 50 mg OD |
K⁺ ≤4.5 mmol/L |
| Alternative |
Alpha- or beta-blocker |
If K⁺ high or intolerant |
- 🧪 Monitor K⁺ closely (hyperkalaemia risk)
- 💡 Particularly effective in aldosterone-driven (resistant) HTN
🔁 Practical Titration Strategy
- 📅 Review every 4 weeks after starting or changing dose
- 📊 Use home BP or ABPM where possible
- ⬆️ Up-titrate to max tolerated dose before adding next drug
- ➕ Combine drugs with different mechanisms (A + C + D)
- 🧠 If uncontrolled → check adherence, lifestyle, secondary causes
💡 High-Yield Prescribing Pearls
- 🧬 ACEi/ARB → expect small creatinine rise (haemodynamic effect, not damage)
- 💊 Amlodipine oedema = capillary leak → not fluid overload
- 🧪 Hyponatraemia on thiazide = common exam trap
- ⚡ Resistant HTN often = hyperaldosteronism physiology
- 📉 Biggest benefit = stroke reduction, not just BP lowering
🚨 Hypertensive Crisis
- BP ≥180/120 mmHg
- Assess for end-organ damage:
- 🧠 encephalopathy
- 👁 papilloedema
- 🫀 acute heart failure
- 🧪 AKI
- 👉 Emergency = admit calm quiet area + IV BP control e.g. Labetalol
- 👉 No damage = gradual oral reduction
🥗 Lifestyle Management (ALL Patients)
- ⚖️ Weight loss (most effective non-drug intervention)
- 🧂 Reduce salt intake (<6g/day)
- 🏃 Exercise ≥150 min/week
- 🍷 Limit alcohol
- 🚭 Smoking cessation
💡 Clinical Pearls
- 📊 Always confirm with ABPM — avoids overtreatment
- 🧠 Most benefit comes from stroke reduction, not just MI prevention
- 👵 In elderly → avoid overtreatment → falls risk
- 🫀 Think organ protection not just BP numbers
- 💊 Poor control? → check adherence, technique, secondary causes
🩺 Case Insight (Exam Favourite)
A 65-year-old Black man with BP 162/96 mmHg → start CCB (NOT ACEi first-line).
If uncontrolled → add ACEi → then thiazide.
👉 This reflects low-renin physiology seen in salt-sensitive hypertension.
