Essential Hypertension

Hypertension is persistently elevated blood pressure — defined as office BP ≥140/90 mmHg on repeated measurement, or ABPM 24-hour average ≥130/80 mmHg. BP is graded: Grade 1 (140–159/90–99), Grade 2 (160–179/100–109), and Grade 3 (≥180/≥110). A single elevated reading does not confirm hypertension — repeated measurements on at least two occasions, or ABPM, are required.

Hypertension is called the 'silent killer' because most patients have no symptoms — even with severely elevated BP. Damage accumulates silently for years before a heart attack, stroke, or heart failure occurs. When symptoms do appear, they may include morning headache, visual disturbance, or nosebleeds — but these are unreliable. The only way to detect hypertension is to measure blood pressure.

White-coat hypertension is elevated clinic BP (≥140/90 mmHg) with normal daily-life BP on ABPM (24-hour average <130/80 mmHg). It affects ~20–30% of patients diagnosed with hypertension by clinic measurement alone. True white-coat hypertension does not require antihypertensive medication — confirming it with ABPM avoids unnecessary treatment.

The 2023 ESH Guidelines recommend a systolic BP target of 120–129 mmHg for most treated hypertensive patients who can tolerate therapy. For patients aged over 65, the target is 130–139 mmHg. For CKD, the target is below 130/80 mmHg. Targets should be individualised to prevent dizziness and falls in elderly patients.

Blood pressure should be measured after at least 5 minutes of quiet rest, with the patient seated comfortably and feet flat on the floor. The cuff should be at heart level on the bare upper arm, with the correct cuff size for the arm circumference. Three readings taken 1–2 minutes apart should be averaged. Caffeine, smoking, and exercise should be avoided for 30 minutes before measurement. Home BP monitoring with a validated upper-arm device is recommended for all hypertensive patients, and ABPM is the gold standard for confirming the diagnosis.

In patients with high-normal BP (130–139/85–89 mmHg) or Grade 1 hypertension without high risk features, lifestyle modification is the first-line treatment and can normalise BP without medication in some cases. The DASH diet (rich in fruits, vegetables, and low-fat dairy) reduces systolic BP by up to 11 mmHg. Weight loss of 10 kg reduces systolic BP by approximately 10 mmHg. Regular aerobic exercise (150 minutes per week), salt restriction below 5 g per day, and limiting alcohol to 2 units per day are all additive. However, most patients with Grade 2 or 3 hypertension will require lifelong medication even with optimal lifestyle changes.

Resistant hypertension is defined as BP that remains above target despite treatment with three or more antihypertensive agents of different classes at optimal doses, ideally including a diuretic. It affects approximately 10–15% of treated hypertensive patients. Causes include non-adherence to medication, suboptimal drug combinations, white-coat effect, and secondary causes such as primary hyperaldosteronism, renal artery stenosis, or obstructive sleep apnoea. The PATHWAY-2 trial demonstrated that spironolactone as a fourth-line agent reduces systolic BP by 20–25 mmHg in resistant hypertension. Evaluation includes ABPM confirmation, renal imaging, and screening for secondary causes.

Hypertension in pregnancy carries serious risks for both mother and baby. Chronic hypertension (present before pregnancy or before 20 weeks) increases the risk of pre-eclampsia, placental abruption, preterm birth, and foetal growth restriction. Gestational hypertension develops after 20 weeks and resolves after delivery. Pre-eclampsia is hypertension with proteinuria after 20 weeks — a medical emergency requiring close monitoring and often early delivery. Pregnant women with hypertension should be managed jointly by a cardiologist and obstetrician. Methyldopa, labetalol, and nifedipine are the preferred antihypertensives in pregnancy. ACE inhibitors, ARBs, and spironolactone are contraindicated.