What is hypertension?

Hypertension (high blood pressure) is defined as consistently elevated blood pressure ≥140/90 mmHg in clinic, or ≥135/85 mmHg on home monitoring. It affects approximately 1 in 3 Australian adults and is the leading modifiable risk factor for heart attack, stroke, heart failure and chronic kidney disease worldwide.

Blood pressure classification

Based on 2023 European Society of Hypertension guidelines.

When symptoms do occur

• Headache (especially in severe hypertension or hypertensive urgency)
• Visual disturbance
• Epistaxis (nosebleed)
• Breathlessness (hypertensive heart disease or heart failure)
• Palpitations

Causes

Primary (essential) hypertension — no identifiable single cause. Accounts for 90–95% of cases. Multifactorial: genetic susceptibility, obesity, salt intake, physical inactivity, alcohol, ageing.

Secondary hypertension — identifiable underlying condition. Accounts for 5–10% and should be suspected in young patients, resistant hypertension or with clinical clues:

• Primary aldosteronism (most common secondary cause)
• Renovascular hypertension (renal artery stenosis)
• Chronic kidney disease
• Obstructive sleep apnoea
• Phaeochromocytoma
• Cushing's syndrome
• Coarctation of the aorta
• Medication-related (NSAIDs, OCP, stimulants)

Diagnosis requires multiple elevated readings on separate occasions. A single elevated reading is not diagnostic. Consider:

• Home blood pressure monitoring (HBPM): Average of 7-day readings (morning and evening). More reproducible than clinic measurements. Avoids white-coat effect.
• 24-hour ambulatory BP monitoring (ABPM): Provides nocturnal dipping data (non-dipper/riser pattern associated with worse outcomes).
• Echocardiogram: Assesses for left ventricular hypertrophy (LVH), diastolic dysfunction and hypertensive cardiomyopathy.
• Blood tests: Renal function, electrolytes, fasting glucose, lipid profile, aldosterone/renin ratio (if secondary hypertension suspected).
• Urinalysis: Proteinuria or haematuria may indicate renal involvement or secondary cause.
• Fundoscopy / eye review: Hypertensive retinopathy indicates end-organ damage.

Blood pressure targets (2024 guidelines)

• General adults: <130/80 mmHg
• Older adults (>80 years): 130–139/70–79 mmHg (cautious to avoid hypotension)
• Diabetes: <130/80 mmHg
• Chronic kidney disease: <130/80 mmHg
• Established CVD: <130/80 mmHg

First-line antihypertensive medications

• ACE inhibitors / ARBs: Preferred for diabetes, CKD, heart failure, post-MI.
• Calcium channel blockers (CCBs): Amlodipine, lercanidipine. Effective and well-tolerated. First-line especially in the elderly.
• Thiazide/thiazide-like diuretics: Indapamide preferred over HCTZ. Effective in combination therapy.
• Combination therapy: Most patients require 2–3 agents. Fixed-dose combinations improve adherence.

Resistant hypertension

Defined as BP uncontrolled on 3 antihypertensive medications (including a diuretic) at optimal doses. Requires specialist evaluation to exclude secondary causes and consider adding spironolactone, doxazosin or renal denervation.

• Each 10 mmHg reduction in systolic BP reduces stroke risk by ~35% and coronary event risk by ~25%
• Well-controlled hypertension significantly reduces risk of heart failure, CKD progression and dementia
• Hypertension with LVH carries a markedly elevated cardiovascular risk independent of BP level
• Long-term adherence to therapy is the key determinant of outcomes — treatment is generally lifelong

• Reduce sodium intake to <5 g/day (approximately 1 teaspoon of salt)
• DASH diet (Dietary Approaches to Stop Hypertension) — rich in fruits, vegetables, whole grains, low-fat dairy
• Regular aerobic exercise — 150 min/week of moderate intensity reduces BP by 4–9 mmHg
• Weight loss — every 1 kg of weight loss reduces BP by ~1 mmHg
• Alcohol reduction — limit to ≤2 standard drinks/day
• Stress reduction techniques
• Stop smoking (smoking causes acute BP rises and long-term vascular damage)