Hypertension — Symptoms, Causes & Treatment | MyMedicPlus

Hypertension (high blood pressure) is defined as persistently elevated arterial blood pressure at or above 130/80 mmHg (American Heart Association) or 140/90 mmHg (European and WHO guidelines). Known as the 'silent killer', hypertension typically causes no symptoms until it precipitates a cardiovascular or cerebrovascular catastrophe. It affects 1.28 billion adults worldwide — approximately 1 in 3 adults globally — and is the single most important modifiable risk factor for stroke, heart attack, heart failure, kidney disease, and premature death. The vast majority of hypertension is primary (essential) — resulting from a complex interplay of genetic and lifestyle factors with no single identifiable cause. Ambulatory blood pressure monitoring (ABPM) — 24-hour automated readings — eliminates white-coat effect and masked hypertension and is the gold standard for diagnosis. Hypertension is graded: Grade 1 (mild) 140–159/90–99 mmHg; Grade 2 (moderate) 160–179/100–109 mmHg; Grade 3 (severe) at or above 180/110 mmHg (ESH/ESC 2023). Isolated systolic hypertension (elevated systolic, normal diastolic) is the most common pattern in adults over 60, reflecting arterial stiffening, and carries significant cardiovascular risk requiring treatment.

Primary (essential) hypertension accounts for 90–95% of cases and results from genetic predisposition combined with lifestyle factors and renin-angiotensin-aldosterone system dysregulation. Key modifiable risk factors include excess dietary sodium, obesity (each 5 kg weight gain raises BP by 2–5 mmHg), physical inactivity, alcohol (more than 14 units per week), smoking, and chronic stress. Secondary hypertension (5–10%) has identifiable causes: primary hyperaldosteronism (most common secondary cause), renal artery stenosis, chronic kidney disease, obstructive sleep apnea, pheochromocytoma, Cushing's syndrome, coarctation of the aorta, and certain medications (NSAIDs, oral contraceptives, sympathomimetics). Licorice (glycyrrhizin) inhibits 11-beta-hydroxysteroid dehydrogenase, causing apparent mineralocorticoid excess with hypertension and hypokalaemia. Tyramine in aged cheeses, fermented foods, and certain wines can precipitate hypertensive crisis in patients taking monoamine oxidase inhibitors (MAOIs). Polycythemia vera — excess red blood cell production — causes hypertension through increased blood viscosity.

Hypertension is asymptomatic in the vast majority of patients — the 'silent killer'. Blood pressure readings of even 180/110 mmHg may cause no perceptible symptoms. When symptoms do occur, they typically reflect target organ damage rather than hypertension per se: headache (classically occipital, worse in the morning), visual disturbances (retinal changes), nausea, epistaxis (nosebleeds), or breathlessness (left ventricular hypertrophy progressing to heart failure). Hypertensive emergency (BP above 180/120 mmHg with acute target organ damage) presents with severe headache, confusion, visual loss, chest pain, or acute pulmonary edema and requires emergency treatment. Morning hypertension (blood pressure surge on waking) is associated with significantly increased cardiovascular event risk — morning is the peak time for MI, stroke, and sudden death. Renovascular hypertension from renal artery stenosis may present with flash pulmonary oedema (recurrent episodic pulmonary oedema despite preserved EF), a clinical clue to bilateral renal artery stenosis.

Hypertension is diagnosed when blood pressure is persistently above 130/80 mmHg (AHA) or 140/90 mmHg (ESC) on two or more separate readings on different occasions. Ambulatory blood pressure monitoring (ABPM) over 24 hours is the gold standard, confirming sustained hypertension and detecting white-coat hypertension and masked hypertension. Investigations assess for secondary causes (serum potassium, renal function, aldosterone-renin ratio) and evaluate target organ damage: echocardiography (left ventricular hypertrophy), renal function and urine ACR, fundoscopy (hypertensive retinopathy), and ECG. Self-monitored blood pressure (SMBP) using validated home monitors should be performed as duplicate measurements 1–2 minutes apart, twice daily, for 7 days — the average of day 2–7 readings provides the home BP value. The validated British Hypertension Society criteria for home BP: hypertension confirmed if average is at or above 135/85 mmHg.

Lifestyle modifications form the foundation: sodium restriction (below 2 g per day — reduces BP by 5–6 mmHg), DASH diet, regular aerobic exercise (30 minutes, 5 days per week — reduces BP by 5–8 mmHg), alcohol reduction, smoking cessation, and weight loss (each 10 kg reduces BP by 6 mmHg). First-line antihypertensive drug classes: ACE inhibitors (ramipril, perindopril) or ARBs (losartan, candesartan) — preferred in diabetics and CKD; calcium channel blockers (amlodipine) — excellent for elderly; thiazide/thiazide-like diuretics (indapamide). Most patients need 2–3 drug combinations for optimal BP control. Target: below 130/80 mmHg for most adults. Single-pill combination (SPC) therapy — fixed-dose combination tablets containing 2 or 3 antihypertensives — dramatically improves adherence (the most common reason for inadequate BP control) and should be the preferred strategy over multiple separate tablets. The SPRINT trial showed that intensive systolic BP target below 120 mmHg reduced cardiovascular events by 25% compared to standard target below 140 mmHg, but with higher rates of hypotension, acute kidney injury, and electrolyte disturbance — applicable to non-diabetic high-risk adults without stroke history.

Hypertension is the leading global risk factor for premature death. Each 20 mmHg rise in systolic BP above 115 mmHg doubles cardiovascular mortality. Complications include stroke (hypertension is responsible for over 50% of strokes), coronary artery disease and heart attack, heart failure (from pressure overload causing LV hypertrophy), hypertensive nephropathy leading to chronic kidney disease, peripheral arterial disease, and hypertensive retinopathy causing visual impairment. Aortic dissection and aortic aneurysm are directly related to sustained hypertension. Each 10 mmHg reduction in systolic blood pressure reduces stroke risk by approximately 35%, heart disease risk by 25%, and all-cause mortality by 13% (Ettehad et al., Lancet 2016 meta-analysis). Malignant hypertension (BP above 180/120 mmHg with papilloedema and end-organ damage) causes hypertensive encephalopathy, acute kidney injury, and microangiopathic haemolytic anaemia — requires controlled reduction in ICU (too rapid reduction can cause watershed infarction).

Population-level sodium reduction, tobacco control policies, and access to affordable antihypertensive medications are the most impactful public health interventions. For individuals: reduce dietary salt (processed foods account for 75% of sodium intake), achieve and maintain healthy weight, exercise regularly, limit alcohol, quit smoking, and manage stress. Regular BP screening from age 18 — at least every 5 years for normal BP, annually from age 40 or if borderline. Once antihypertensive therapy is started, consistency is critical — stopping treatment causes rapid BP rebound and significantly increases stroke and heart attack risk.

Call emergency services (999/911) or attend Emergency Department immediately for: blood pressure above 180/120 mmHg with any of the following symptoms — severe headache, visual disturbance (blurred or loss of vision), chest pain or tightness, breathlessness, confusion or altered consciousness, one-sided weakness or facial drooping, or loss of speech — this is a hypertensive emergency with active target organ damage (hypertensive encephalopathy, aortic dissection, acute pulmonary oedema, or stroke); symptoms of acute stroke (FAST: Face drooping, Arm weakness, Speech difficulty, Time to call 999) regardless of blood pressure reading. See your GP within 24-48 hours for: blood pressure above 180/120 mmHg without symptoms — hypertensive urgency requiring same-day medication review or adjustment; a single very high reading at home with no symptoms — recheck at pharmacy or GP; starting a new antihypertensive medication — review at 4-6 weeks. See your GP routinely for: blood pressure readings consistently above 135/85 mmHg on home monitoring; annual blood pressure check if you have diabetes, kidney disease, or previous cardiovascular event.