Hypertension — Causes, Symptoms & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Hypertension (high blood pressure) is defined as a persistent elevation of blood pressure at or above 130/80 mmHg (AHA 2017) or 140/90 mmHg (ESH/NICE guidelines), measured on at least two separate occasions. It is one of the most prevalent chronic conditions globally — affecting 1.28 billion adults aged 30-79 — and is the leading modifiable risk factor for heart attack, stroke, heart failure, chronic kidney disease, and premature death. Blood pressure is expressed as systolic (the pressure when the heart contracts) over diastolic (the pressure when the heart relaxes). Hypertension is classified as primary (essential — accounting for 90-95% of cases, with no single identifiable cause) or secondary (5-10% of cases — caused by an identifiable condition such as renal artery stenosis, primary hyperaldosteronism, or obstructive sleep apnoea). It is often called the 'silent killer' because it causes no symptoms until target organ damage (heart, kidneys, brain, eyes, vessels) has occurred.

Primary hypertension (essential): multifactorial — results from the complex interaction of genetic predisposition and environmental factors including high sodium intake (population average of 10g/day, far exceeding the 5g WHO recommendation), physical inactivity, obesity (particularly central adiposity), excess alcohol consumption (above 14 units per week), chronic stress, and advancing age (arterial stiffening reduces vascular compliance). Family history of hypertension or early cardiovascular disease is a significant risk factor. Secondary hypertension: must be excluded in younger patients (under 30), those with resistant hypertension, or those with sudden-onset severe hypertension. Causes include: primary hyperaldosteronism (aldosterone-secreting adrenal adenoma — most common secondary cause, responsible for 5-10% of all hypertension), chronic kidney disease (loss of sodium excretion and renin-angiotensin axis activation), renal artery stenosis (fibromuscular dysplasia in younger women; atherosclerotic in older men), obstructive sleep apnoea (causes sympathetic nervous system activation), phaeochromocytoma (catecholamine-secreting tumour — episodic severe hypertension, sweating, palpitations), Cushing's syndrome, primary hyperaldosteronism, coarctation of the aorta, and drugs (NSAIDs, COCPs, sympathomimetics, steroids, liquorice).

Primary hypertension is almost universally asymptomatic until complications develop — this is why population screening through routine blood pressure measurement is essential. Non-specific symptoms sometimes reported (not specific to hypertension): headaches (particularly occipital, in the morning — more associated with severe hypertension or hypertensive urgency), dizziness, and visual disturbances. These are not reliable indicators of blood pressure elevation and cannot be used to diagnose or monitor hypertension. Hypertensive urgency and emergency: severe hypertension (BP above 180/120 mmHg) with or without acute end-organ damage. Symptoms of hypertensive emergency include severe headache, confusion or altered consciousness (hypertensive encephalopathy), chest pain (aortic dissection, acute MI), acute shortness of breath (acute pulmonary oedema), and visual changes (hypertensive retinopathy, papilloedema). Fundoscopic signs of target organ damage: arteriovenous nipping, flame haemorrhages, cotton wool spots (Grade III retinopathy), papilloedema (Grade IV — malignant hypertension). Long-term complications: stroke, myocardial infarction, heart failure (hypertensive cardiomyopathy), chronic kidney disease (hypertensive nephrosclerosis), peripheral arterial disease, and retinopathy.

Diagnosis requires accurate blood pressure measurement: clinic BP should be confirmed on at least 2-3 separate occasions (to exclude 'white coat hypertension' — elevated BP in clinical settings only). ABPM (ambulatory blood pressure monitoring — 24-hour automatic readings) and HBPM (home blood pressure monitoring) are more accurate than clinic readings and are the preferred diagnostic methods in UK NICE guidelines. Diagnosis of hypertension by ABPM: daytime average 135/85 mmHg or above. Staging (AHA): Stage 1: 130-139/80-89 mmHg; Stage 2: 140/90 mmHg or above. Initial investigations to screen for end-organ damage and identify secondary causes: blood tests (renal function/eGFR, electrolytes — low potassium suggests hyperaldosteronism; fasting glucose, HbA1c, lipid profile); urine dipstick (haematuria, proteinuria — renal disease); ECG (left ventricular hypertrophy — Sokolow index, voltage criteria); fundoscopy (hypertensive retinopathy). Echocardiography if LVH suspected or symptomatic heart disease. Renal ultrasound if secondary renal cause suspected. Aldosterone:renin ratio for primary hyperaldosteronism. 24-hour urine catecholamines and metanephrines for phaeochromocytoma.

Treatment decisions balance cardiovascular risk reduction against medication burden. Target BP: below 130/80 mmHg for most adults (AHA); below 140/90 mmHg for low-risk patients (NICE). For those over 80: below 150/90 mmHg (higher target reduces fall and syncope risk). Lifestyle modifications (first-line for Stage 1, adjunct to medication for all): dietary sodium reduction (below 5g/day — DASH diet reduces BP by 8-14 mmHg), regular aerobic exercise (150 minutes moderate intensity per week — reduces BP 5-8 mmHg), weight loss (1 mmHg reduction per 1 kg lost), alcohol reduction (below 14 units/week), smoking cessation, and Mediterranean or DASH diet. Pharmacological treatment — first-line drug classes (used alone or in combination): ACE inhibitors (ramipril, lisinopril — first choice for diabetes, heart failure, CKD with proteinuria; risk of cough in 10-15% — switch to ARB), ARBs (losartan, candesartan — for ACE inhibitor intolerance; similar efficacy), calcium channel blockers (amlodipine, felodipine — first-line for older patients and Afro-Caribbean patients; also effective antianginals), and thiazide-like diuretics (indapamide, chlorthalidone — for most patients without contraindications). Fixed-dose combination tablets improve adherence. Beta-blockers (bisoprolol, atenolol) are used for hypertension with heart failure, angina, or arrhythmia (not first-line for uncomplicated hypertension). Spironolactone (fourth-line, potassium-sparing): highly effective for resistant hypertension and primary hyperaldosteronism. Resistant hypertension (BP uncontrolled on 3 antihypertensives including a diuretic): reassess secondary causes, medication adherence, diet. Renal denervation (catheter-based ablation of renal sympathetic nerves) is available for truly resistant hypertension in specialist centres.

Stroke is the most devastating acute complication — hypertension is responsible for approximately 54% of all strokes globally. Each 20 mmHg rise in systolic BP above 115 mmHg doubles cardiovascular mortality. Chronic hypertension causes left ventricular hypertrophy (LVH — concentric thickening of the left ventricle), which progresses to hypertensive cardiomyopathy and heart failure if untreated. Hypertensive nephropathy — damage to the small arteries of the kidney — leads to chronic kidney disease and eventually end-stage renal disease requiring dialysis. Hypertensive retinopathy causes progressive visual impairment and, in malignant hypertension (BP above 180/120 mmHg with papilloedema), can cause sudden visual loss. Aortic dissection and aortic aneurysm are directly related to sustained hypertension-mediated arterial wall weakness. Peripheral arterial disease from hypertension-accelerated atherosclerosis causes claudication, critical limb ischaemia, and amputation risk.

Hypertension is largely preventable through population-level lifestyle modification. Dietary salt reduction: cutting daily sodium intake from the current global average of 10g to below 5g/day can reduce mean population systolic BP by 2-7 mmHg and prevent an estimated 1.65 million cardiovascular deaths annually (WHO). Food industry reformulation, food labelling, and personal vigilance about hidden salt in processed foods are all required. Regular physical activity: 150-300 minutes of moderate aerobic exercise per week is associated with a 5-8 mmHg BP reduction and significant cardiovascular risk reduction independent of BP. Maintaining healthy weight: obesity (BMI above 30) is a major risk factor — even modest weight loss of 5-10% of body weight significantly reduces blood pressure. Limit alcohol: men and women should not regularly exceed 14 units per week (NICE/AHA); binge drinking should be avoided. Smoking cessation: reduces cardiovascular event risk (smoking causes endothelial dysfunction and acute BP elevation). DASH (Dietary Approaches to Stop Hypertension) diet: rich in fruits, vegetables, whole grains, low-fat dairy; limits saturated fat and red meat — shown to reduce systolic BP by 11 mmHg. Annual blood pressure measurement for all adults over 40 in primary care.

All adults should have blood pressure checked at least every 5 years (annually if previously elevated or above age 40). See a GP if home blood pressure readings are consistently 135/85 mmHg or above, or if you have cardiovascular risk factors (diabetes, obesity, smoking, family history of early heart disease). Seek immediate emergency care for severe headache with visual disturbance, confusion, chest pain, or sudden neurological symptoms — these may indicate hypertensive emergency or stroke. Blood pressure above 180/120 mmHg requires same-day emergency medical evaluation even if asymptomatic (hypertensive urgency). If you have established hypertension and develop breathlessness on exertion, ankle swelling, or chest pain, see a doctor urgently — these may indicate heart failure or coronary artery disease. Pregnant women developing hypertension require urgent assessment for pre-eclampsia.