May 14: World Hypertension Day

Manuel Van den Broucke, sports, society and politics correspondent, May 14, 2025

Definition and causes of high blood pressure

High blood pressure (hypertension) is a persistent elevation of the pressure exerted by blood on the artery walls. The main cause is excess sodium intake: a salt intake > 5 g/day increases plasma volume and stimulates the renin-angiotensin-aldosterone system (RAAS), a hormonal system that regulates blood pressure. In addition, being overweight or obese increases renal blood flow, while a sedentary lifestyle reduces nitric-oxide-dependent vasodilation - a molecule that keeps arteries flexible. Excessive alcohol consumption (> 14 units/week), smoking, chronic stress and potassium deficiency further worsen blood pressure. Common medications, such as non-steroidal anti-inflammatory drugs, combined oral contraceptives, certain antidepressants or decongestants containing pseudoephedrine, can also trigger hypertension. Genetically, more than 30 loci have been linked to blood pressure regulation, and a first-degree family history doubles the risk of hypertension before age 55.

Available treatments

When lifestyle and dietary measures (sodium restriction < 4 g/day, 150 min/week of aerobic activity, 5% weight loss, smoking cessation) are not enough to reach the target of < 140/90 mmHg - or < 130/80 mmHg for high-risk patients - drug therapy is started. The five classes of medication are: thiazide and related diuretics, which reduce extracellular volume; angiotensin-converting enzyme inhibitors (ACE inhibitors), which block the production of angiotensin II; angiotensin II receptor blockers (ARBs), which prevent it from acting on vascular receptors; dihydropyridine calcium channel blockers, which relax the muscles of the arterioles; and beta-blockers, which reduce adrenergic stimulation of the heart. The choice of treatment depends on the clinical profile: ACE inhibitors and ARBs are recommended for diabetic patients to preserve kidney function, beta-blockers are indicated after a heart attack, and calcium channel blockers are useful for vasospastic angina. Thiazide diuretics are preferred in elderly patients and in cases of fluid overload, while spironolactone, an aldosterone antagonist, is an effective option in resistant forms of hypertension, meaning cases not controlled despite three well-managed medications, including a diuretic.