Hypertension

Chronic elevation of systemic arterial blood pressure, a major modifiable risk factor for cardiovascular disease, stroke, and chronic kidney disease. Defined per major guidelines (thresholds vary slightly by society, ACC/AHA vs. ESC/NICE):

• ACC/AHA: ≥130/80mmHg (Stage 1: 130-139/80-89; Stage 2: ≥140/90)

• ESC/NICE/WHO: ≥140/90mmHg (clinic), ≥135/85mmHg (home/ambulatory average)

Classified by:

• Primary (essential) hypertension: ~90-95% of cases, multifactorial (genetic, lifestyle, age-related vascular changes), no single identifiable cause

• Secondary hypertension: identifiable underlying cause, renal (renal artery stenosis, CKD, polycystic kidney disease), endocrine (primary aldosteronism, pheochromocytoma, Cushing's syndrome, hyperthyroidism/hypothyroidism, hyperparathyroidism), obstructive sleep apnea, coarctation of aorta, drug-induced (NSAIDs, oral contraceptives, corticosteroids, decongestants, cocaine)

• Hypertensive urgency: severely elevated BP (≥180/120) without acute end-organ damage

• Hypertensive emergency: severely elevated BP WITH acute end-organ damage (encephalopathy, ACS, aortic dissection, acute pulmonary edema, acute kidney injury, eclampsia)

• Usually asymptomatic ("silent killer"): detected on routine screening

• Severe hypertension may cause: headache, visual disturbance, epistaxis (poorly correlated with BP level, often coincidental)

• Hypertensive emergency symptoms depend on organ affected: chest pain (ACS, dissection, tearing pain radiating to back), dyspnea (pulmonary edema), focal neurological deficit/severe headache/altered consciousness (hypertensive encephalopathy, stroke), visual disturbance (papilledema, retinal hemorrhages)

• Examination: fundoscopy (hypertensive retinopathy grading, arteriolar narrowing, AV nicking, hemorrhages/exudates, papilledema in malignant hypertension), signs of secondary causes (radiofemoral delay, coarctation; abdominal bruit, renal artery stenosis; central obesity/striae, Cushing's; paroxysmal symptoms with palpitations/sweating/headache, pheochromocytoma)

• Target organ damage assessment: LVH (examination/ECG/echo), retinopathy, proteinuria/renal impairment, peripheral arterial disease

• Confirm with out-of-office measurement before diagnosing (avoid white-coat effect): ambulatory BP monitoring (ABPM, gold standard) or home BP monitoring (HBPM), average of readings over several days

• Proper technique essential: seated, back supported, arm at heart level, appropriate cuff size, no caffeine/exercise/smoking 30 min prior, average of ≥2 readings

Investigations (baseline, all patients):

• U&E/creatinine/eGFR (renal function, baseline before ACEi/ARB)

• Urinalysis (proteinuria, hematuria: renal disease)

• Fasting glucose/HbA1c, lipid profile (cardiovascular risk assessment)

• ECG (LVH, ischemia, arrhythmia)

• Consider echocardiogram if LVH suspected or heart failure symptoms

Screen for secondary causes if: age <30 with no risk factors/family history, resistant hypertension (uncontrolled on 3 drugs including diuretic), sudden onset/worsening, hypokalemia (aldosteronism), paroxysmal symptoms (pheochromocytoma), aldosterone:renin ratio, plasma/urine metanephrines, renal artery imaging, overnight dexamethasone suppression test as indicated.

Cardiovascular risk assessment: calculate 10-year CVD risk (e.g., ASCVD risk calculator, QRISK) to guide treatment intensity and statin decision.

Lifestyle modification (all patients, foundation of treatment):

• Sodium restriction (<2g/day, ~5g salt), DASH diet (fruits, vegetables, low-fat dairy, reduced saturated fat)

• Weight loss if overweight/obese (each kg loss ~1mmHg SBP reduction)

• Regular aerobic exercise (≥150 min/week moderate intensity)

• Alcohol moderation, smoking cessation

• Stress reduction

Pharmacological treatment: initiate based on BP level, CV risk, and target organ damage; per ACC/AHA/NICE algorithms:

• First-line agents (choice influenced by age, ethnicity, comorbidities):

• ACE inhibitors (lisinopril 10mg od, ramipril 2.5-10mg od) or ARBs (losartan 50mg od, candesartan 8-32mg od), preferred in younger patients (<55, non-Black), diabetes, CKD with proteinuria, heart failure; avoid combining ACEi+ARB; monitor U&E/creatinine and K+ after initiation

• Calcium channel blockers (amlodipine 5-10mg od): preferred first-line in older patients (≥55) and Black patients of any age (per NICE); effective, well-tolerated

• Thiazide/thiazide-like diuretics (indapamide 1.5-2.5mg od, chlorthalidone 12.5-25mg od), alternative first-line, particularly useful add-on

• Step 2: combination therapy (ACEi/ARB + CCB, or ACEi/ARB + thiazide), combination therapy from the outset increasingly recommended for Stage 2/higher BP given superior efficacy and adherence with fixed-dose combinations

• Step 3: triple therapy (ACEi/ARB + CCB + thiazide-like diuretic)

• Step 4 (resistant hypertension): add spironolactone 25-50mg od (if K+ <4.5 and eGFR adequate, effective given frequent occult primary aldosteronism contribution) or alpha-blocker (doxazosin) or beta-blocker if not tried; consider secondary causes workup and specialist referral

• Beta-blockers: not first-line for uncomplicated hypertension but indicated with compelling comorbid indications (post-MI, heart failure, atrial fibrillation rate control), e.g., bisoprolol 2.5-10mg od

Hypertensive urgency: gradual BP reduction over 24-48 hours with oral agents, no need for IV therapy or hospital admission in absence of end-organ damage, rapid reduction risks cerebral/coronary hypoperfusion.

Hypertensive emergency: hospital/ICU admission, IV antihypertensives (labetalol infusion, nicardipine, sodium nitroprusside, GTN for pulmonary edema/ACS) (target: reduce MAP by no more than 25% in first hour (except aortic dissection) target SBP <120 within 20 min, and ischemic stroke where permissive hypertension often preferred acutely unless thrombolysis planned or extreme elevation).

Targets: generally <130/80mmHg for most adults (ACC/AHA) or <140/90 (ESC/NICE, more lenient in elderly/frail, individualize, avoid orthostatic symptoms/falls in frail elderly); tighter targets in diabetes with proteinuria/CKD per some guidelines.

Monitoring: BP reassessment 2-4 weeks after medication changes, then periodically once controlled (every 3-6 months); annual review of renal function, electrolytes on ACEi/ARB/diuretics, cardiovascular risk reassessment.