Why Hypertension Management Is Examined
Hypertension affects approximately 30% of UK adults and is the leading modifiable risk factor for stroke, MI, heart failure, and CKD. OSCEs examine it in prescribing stations (initiate antihypertensive therapy), communication stations (counsel a newly diagnosed hypertensive patient), and clinical reasoning (this patient's BP is 175/105 — what is your plan?). Examiners test NICE-aligned step therapy, lifestyle counselling, and safe prescribing.
Diagnosis — NICE 2023 Thresholds
| Stage | Clinic BP | ABPM/HBPM |
|---|---|---|
| Normal | Below 130/85 | — |
| High normal | 130-139/85-89 | — |
| Stage 1 HTN | 140-159/90-99 | ABPM day average 135/85 or above |
| Stage 2 HTN | 160-179/100-109 | ABPM day average 150/95 or above |
| Stage 3 (severe) | 180/120 or above | — (treat immediately) |
💡 Tip
All Stage 1 or 2 hypertension confirmed by clinic readings must be validated with ABPM or HBPM before starting treatment — unless there is evidence of end-organ damage, established CVD, or the BP is 180/120 or above. ABPM is more reproducible, eliminates white-coat effect, and predicts cardiovascular outcome better than clinic readings.
When to Start Drug Treatment (NICE 2023)
| Stage | Treat if |
|---|---|
| Stage 1 (140-159/90-99 confirmed on ABPM) | 10-year CVD risk above 10%, OR target organ damage (LVH, CKD, retinopathy, previous CVD) |
| Stage 2 (160-179/100-109 confirmed on ABPM) | Always offer drug treatment |
| Stage 3 (180/120 or above) | Same-day assessment; start treatment urgently |
The NICE AB/CD Rule — Step Therapy
🧠 Mnemonic
AB/CD — drug classes by patient group:
- A = ACE inhibitor or ARB (angiotensin II receptor blocker)
- B = Beta-blocker (not a first-line standalone antihypertensive for most)
- C = Calcium channel blocker (amlodipine)
- D = Diuretic — thiazide-like (indapamide or chlortalidone — preferred over bendroflumethiazide)
Step 1:
- Under 55 and not black African/Caribbean: A (ACE inhibitor — e.g., ramipril 2.5 mg OD)
- 55 or over, OR black African/Caribbean at any age: C (amlodipine 5 mg OD)
Step 2: A + C (combination)
Step 3: A + C + D (triple combination)
Step 4 (resistant hypertension — BP above target on A+C+D):
- Check adherence and 24-hour ABPM first
- Add spironolactone 25 mg OD (if potassium below 4.5 mmol/L)
- Or increase diuretic dose / add beta-blocker or alpha-blocker
- Refer to specialist
Treatment Targets (NICE 2023)
| Patient group | Clinic BP target | ABPM/HBPM target |
|---|---|---|
| Under 80 years | Below 140/90 | Below 135/85 |
| 80 years and above | Below 150/90 | Below 145/85 |
| Type 1 or 2 diabetes | Below 140/90 (below 130/80 if nephropathy or CVD) | |
| CKD with proteinuria | Below 130/80 |
Lifestyle Modification — First-Line for All Patients
🧠 Mnemonic
DASHES — lifestyle interventions:
- D ASH diet (Dietary Approaches to Stop Hypertension) — low sodium, high potassium, fruit, vegetables, whole grains
- A lcohol reduction (no more than 14 units/week; avoid binge drinking)
- S odium restriction (below 6 g salt/day; avoid processed foods)
- H eight and weight (BMI reduction — each 1 kg reduces BP by approximately 1 mmHg)
- E xercise (150 minutes/week moderate intensity — reduces BP by 5-8 mmHg)
- S moking cessation (not a direct BP reducer, but essential CVD risk reduction)
Secondary Causes of Hypertension
Always consider secondary causes, especially in: age below 40, resistant hypertension, sudden onset, hypokalaemia, symptoms suggesting phaeochromocytoma or Cushing's.
| Cause | Clues | Investigation |
|---|---|---|
| Renal parenchymal disease | Haematuria, proteinuria, CKD history | U&E, urine PCR, renal USS |
| Renovascular (renal artery stenosis) | Young woman (FMD) or atherosclerotic (elderly), flash pulmonary oedema | Renal Doppler USS, CT/MR angiography |
| Primary hyperaldosteronism (Conn's) | Hypokalaemia, resistant HTN | Aldosterone:renin ratio |
| Phaeochromocytoma | Paroxysmal HTN, headache, sweating, palpitations | Plasma metanephrines, 24-hour urine catecholamines |
| Cushing's syndrome | Central obesity, striae, easy bruising, proximal myopathy | 24-hour urinary cortisol, overnight dexamethasone suppression |
| Thyroid disease | Hypo/hyperthyroidism | TFTs |
| Obstructive sleep apnoea | Snoring, obesity, daytime somnolence | Sleep study |
| Coarctation of the aorta | Radiofemoral delay, reduced BP in legs, young patient | CT/echo |
ACE Inhibitor Prescribing Safety
⚠️ Red Flag
ACE inhibitors and ARBs require monitoring:
- Check U&E and creatinine at baseline, 1-2 weeks after starting or dose increase, then annually
- An increase in creatinine of up to 30% or eGFR decrease of up to 25% is acceptable — do not stop
- Stop if: creatinine rises more than 30% (suggests bilateral renal artery stenosis) or K+ above 6.0 mmol/L
- Contraindicated in pregnancy — teratogenic (fetotoxic from 2nd trimester)
- Common side effect: dry cough (ACE inhibitor-specific — bradykinin accumulation) — switch to ARB
Frequently Asked Questions
"Why are thiazide-like diuretics (indapamide) preferred over bendroflumethiazide?"
Indapamide and chlortalidone have longer half-lives (enabling consistent 24-hour BP control), more evidence for cardiovascular outcomes, and are less metabolically disruptive than bendroflumethiazide. The ALLHAT trial (chlortalidone) and ACCOMPLISH trial supported the use of newer thiazide-like diuretics. NICE 2023 now specifically recommends indapamide or chlortalidone over bendroflumethiazide as the thiazide-like diuretic of choice.
"Why are calcium channel blockers preferred in older and black African/Caribbean patients?"
Older patients and black African/Caribbean patients have lower plasma renin activity — meaning the renin-angiotensin system is less active and ACE inhibitors/ARBs are less effective as monotherapy. CCBs and diuretics achieve better BP reduction in these groups because they work via renin-independent mechanisms (reducing peripheral vascular resistance and sodium-water retention respectively). This is not an absolute rule — individual response varies — but it is the NICE-recommended starting point.
"What is resistant hypertension?"
Resistant hypertension is defined as a clinic BP above target despite adherence to optimal tolerated doses of three antihypertensive agents of different classes, one of which should be a thiazide-like diuretic (A+C+D). Before adding a fourth agent, confirm true resistance with ABPM (to exclude white-coat effect), review adherence (non-adherence is common), investigate secondary causes, and assess drug interactions (NSAIDs, combined oral contraceptive, steroids, decongestants). Spironolactone is the most effective fourth agent for most patients.
"What are the side effects of each class of antihypertensive?"
ACE inhibitors: dry persistent cough (10-15%), hyperkalaemia, first-dose hypotension, AKI in renal artery stenosis. ARBs: similar to ACEi but no cough (different mechanism). CCBs (dihydropyridine — amlodipine): peripheral oedema (ankle swelling — most common), flushing, headache. Thiazide-like diuretics: hypokalaemia, hyponatraemia, gout (urate retention), impaired glucose tolerance. Beta-blockers: fatigue, cold peripheries, erectile dysfunction, bronchospasm (avoid in asthma).
"How do you manage hypertension in pregnancy?"
Labetalol (alpha and beta blocker) is first-line in all stages of pregnancy. Alternatives: methyldopa (safe but causes depression — not for long-term use), nifedipine. ACE inhibitors, ARBs, and thiazide diuretics are all contraindicated. Target: systolic 135-155 mmHg. Pre-eclampsia (HTN after 20 weeks + proteinuria + ± organ dysfunction) is a medical emergency — may require IV labetalol or magnesium sulphate (for seizure prevention), and ultimately delivery.
Related Posts
- Blood Pressure Measurement OSCE — accurate measurement and postural BP assessment
- Cardiovascular Examination OSCE — examining for hypertensive end-organ damage
- Chronic Kidney Disease OSCE — CKD as both a cause and consequence of hypertension