Key Facts

Hypertension is the single most important modifiable risk factor for cardiovascular disease (CVD), stroke, heart failure, and chronic kidney disease. It is predominantly managed in primary care with lifestyle changes and a stepwise pharmacological approach.

Epidemiology

• Prevalence: 30% of UK adults (rising with age)
• 50% of those aged >60 years
• One-third of hypertensives are undiagnosed
• Contributes to >50% of coronary heart disease and >60% of strokes
• More common in Black African/Caribbean populations (often salt-sensitive, low-renin)

Aetiology

• Primary (essential) hypertension: 90-95% of cases; no identifiable cause; multifactorial (genetic, environmental)
• Secondary hypertension (5-10%): renal artery stenosis, phaeochromocytoma, Conn syndrome (primary hyperaldosteronism), Cushing syndrome, coarctation of aorta, CKD, oral contraceptive pill, NSAIDs, liquorice

Pathophysiology

• Complex interplay of increased cardiac output and/or increased peripheral vascular resistance
• Renin-angiotensin-aldosterone system (RAAS) activation
• Sympathetic nervous system overactivity
• Endothelial dysfunction (reduced nitric oxide)
• Sodium retention and volume expansion
• Arterial stiffness and remodelling
• Target organ damage: left ventricular hypertrophy, nephrosclerosis, retinopathy, cerebrovascular disease

Most Patients Are Asymptomatic

• Hypertension is usually detected incidentally on routine BP measurement
• Headache is NOT a reliable symptom (myth)

Target Organ Damage Presentation

• Cardiovascular: angina, MI, heart failure, peripheral vascular disease
• Cerebrovascular: TIA, stroke
• Renal: CKD, proteinuria
• Retinal: hypertensive retinopathy (flame haemorrhages, cotton-wool spots, papilloedema)

Hypertensive Emergency/Urgency

• Stage 3 (severe): clinic BP ≥180/120 mmHg
• With target organ damage: hypertensive emergency (immediate assessment)
• Without target organ damage: hypertensive urgency (same-day assessment, start treatment)

Red Flags (Suspect Secondary Hypertension)

• Age <40 years with significant hypertension
• Treatment-resistant hypertension (≥3 drugs at adequate doses)
• Sudden onset or worsening of hypertension
• Hypokalaemia (Conn syndrome)
• Episodes of headache, sweating, palpitations (phaeochromocytoma)
• Renal bruit (renal artery stenosis)
• Cushingoid features
• Radio-femoral delay (coarctation)

Bedside

• Clinic BP: measured on both arms initially; use the higher reading arm for future measurements
• ABPM: gold standard for diagnosis; at least 14 readings during waking hours; daytime average ≥135/85 confirms hypertension
• HBPM: if ABPM not tolerated; BD for 7 days; average of days 2-7; ≥135/85 confirms hypertension
• Urinalysis: proteinuria, haematuria (renal disease)
• ECG: left ventricular hypertrophy (LVH)

Bloods

• U&Es (baseline renal function, K+)
• eGFR
• Lipid profile (total cholesterol, HDL, TC:HDL ratio)
• HbA1c or fasting glucose (diabetes screening)
• FBC
• LFTs (baseline before statin)

Imaging

• Not routinely required
• Echocardiography: if LVH suspected or heart failure symptoms
• Renal ultrasound: if CKD or suspected renal artery stenosis

Special Tests

• QRISK3: 10-year cardiovascular risk assessment
• Aldosterone:renin ratio: if Conn syndrome suspected
• 24h urinary metanephrines: if phaeochromocytoma suspected
• Urine ACR: to assess for diabetic/hypertensive nephropathy

Non-pharmacological (All Patients)

• Dietary: reduce salt intake to <6g/day, DASH diet, increase fruit and vegetables, reduce saturated fat
• Weight loss: target BMI <25; each kg lost reduces BP by ~1mmHg
• Exercise: moderate aerobic exercise 150 minutes/week
• Alcohol: limit to ≤14 units/week
• Smoking cessation: does not directly reduce BP but dramatically reduces CVD risk
• Reduce caffeine intake

Pharmacological (NICE NG136 Stepwise Approach)

• Step 1:
  • Age <55 or any age with T2DM: ACEi (ramipril 1.25-10mg OD) or ARB (candesartan 8-32mg OD, losartan 50-100mg OD)
  • Age ≥55 or Black African/Caribbean (without DM): CCB (amlodipine 5-10mg OD)
  • If CCB not suitable: thiazide-like diuretic (indapamide 2.5mg OD)
• Step 2: ACEi/ARB + CCB
• Step 3: ACEi/ARB + CCB + thiazide-like diuretic (indapamide 2.5mg OD)
• Step 4 (resistant hypertension):
  • If K+ ≤4.5: add spironolactone 25mg OD (PATHWAY-2 trial — most effective add-on)
  • If K+ >4.5: add alpha-blocker (doxazosin 4-8mg MR) or beta-blocker (bisoprolol 5-10mg)
  • Consider specialist referral

Target BP

• <140/90 clinic (<135/85 ABPM/HBPM): for patients <80 years
• <150/90 clinic (<145/85 ABPM/HBPM): for patients ≥80 years
• <130/80 for patients with CKD and diabetes with ACR ≥70 (NICE NG136)

Monitoring

• U&Es 1-2 weeks after starting ACEi/ARB or dose change (check for AKI, hyperkalaemia)
• Monthly BP until at target, then at least annually

Referral Criteria

• Specialist referral: resistant hypertension (step 4), suspected secondary hypertension, young age (<40), significant target organ damage
• Emergency assessment: stage 3 hypertension (≥180/120) with evidence of target organ damage

• Lowering SBP by 10mmHg reduces stroke risk by 27%, MI risk by 17%, and heart failure by 28% (Lancet meta-analysis 2016)
• Untreated hypertension: 50% die from coronary heart disease, 33% from stroke, 10-15% from renal failure
• Treated hypertension: life expectancy approaches that of normotensive individuals
• Resistant hypertension affects 10-20% of treated patients
• SPRINT trial: intensive BP target <120mmHg SBP reduced cardiovascular events by 25% vs standard (<140mmHg); but higher rates of hypotension, AKI, electrolyte disturbance

NICE NG136 — Hypertension Treatment Algorithm Summary

Key Landmark Trials in Hypertension

BP Classification (NICE NG136)