Overview
Hypertension is persistently elevated blood pressure in the arteries. It is defined as readings consistently at or above 140/90 mmHg in clinic. Often called the silent killer because it causes no symptoms for years while steadily damaging the heart, kidneys, brain, and blood vessels. It is the single most important modifiable risk factor for cardiovascular disease worldwide.
How common is it?
About 1 in 3 adults in the UK has hypertension, and around half are undiagnosed. Prevalence increases markedly with age: over 60% of adults above 65 are affected.
Causes and risk factors
Primary (essential) hypertension has no single cause and accounts for 90 to 95% of cases. Secondary hypertension has an identifiable cause.
Common risk factors
- Age (arterial stiffness increases with age)
- Family history
- Excess dietary salt
- Obesity
- Physical inactivity
- Alcohol excess
- Chronic stress
- Secondary causes: renal artery stenosis, chronic kidney disease, primary hyperaldosteronism, phaeochromocytoma, obstructive sleep apnoea, thyroid disorders
Symptoms
- Usually none — hypertension is asymptomatic in the vast majority of cases
- Headache (only in severe hypertension)
- Blurred vision
- Nosebleeds (in severe cases)
- Hypertensive crisis: severe headache, chest pain, shortness of breath, confusion
When to see a doctor
All adults should have blood pressure checked at least every 5 years. Seek immediate assessment for blood pressure above 180/120 mmHg, or if associated with chest pain, severe headache, or visual disturbance.
Diagnosis
Clinic readings, home monitoring, or ambulatory blood pressure monitoring (ABPM) over 24 hours. Blood tests and urine check for end-organ damage and secondary causes. ECG and echocardiogram if cardiac involvement suspected.
Treatments
Lifestyle modification
DASH diet (high fruit, vegetables, low salt), weight loss, aerobic exercise 150 minutes per week, alcohol reduction, and smoking cessation can reduce blood pressure by 5 to 10 mmHg each.
ACE inhibitors or ARBs
First-line for hypertension in patients under 55 or with diabetes or kidney disease. Ramipril, lisinopril, losartan. ACE inhibitors are teratogenic and should not be used in pregnancy.
Calcium channel blockers
First-line for patients over 55 and in people of African or Caribbean origin. Amlodipine is widely used. Effective and well tolerated. Side effects include ankle swelling.
Thiazide-like diuretics
Indapamide or chlortalidone used when two agents are required. Added as third agent in resistant hypertension together with ACE inhibitor/ARB and CCB (the ACD combination).
Self-care and lifestyle
- Reduce dietary salt to under 6g (one teaspoon) per day
- Eat a diet rich in fruit, vegetables, whole grains, and low-fat dairy
- Exercise aerobically for at least 30 minutes on most days
- Limit alcohol to no more than 14 units per week
- Maintain a healthy BMI
Prevention
Healthy lifestyle from early adulthood delays or prevents hypertension. Regular blood pressure monitoring allows early detection before end-organ damage occurs.