Essential hypertension: what it is, symptoms, diagnosis and treatment

Blood pressure is the force of blood against artery walls, written as two numbers such as 130/80: the pressure when the heart beats and the pressure between beats. NICE CKS defines hypertension as persistently raised arterial blood pressure and says it is a risk factor for heart failure, coronary artery disease, stroke, chronic kidney disease, peripheral arterial disease and vascular dementia.

Most people with hypertension have what is called essential or primary hypertension. That does not mean the cause is unknown in a sinister sense; it means no single disease or drug explains it. NICE CKS estimates about 90% of cases are primary and about 10% are secondary. Secondary hypertension, discussed in a separate guide on this site, is more likely to be looked for in younger adults or when blood pressure is unusually severe or resistant to treatment.

The NHS is clear that high blood pressure does not usually cause symptoms and that many people have it without knowing. Headaches, blurred vision and chest pain can occur rarely, but they are not reliable signs, and normal blood pressure can also coexist with those symptoms. Feeling well is therefore not evidence of a normal reading.

The NHS suggests having a check at a pharmacy or GP surgery if you think you may be at risk, or if you are 40 or over and have not had a check for more than five years. It notes that many pharmacies offer free checks for people aged 40 or over. Blood Pressure UK describes who should have a check and how to monitor at home on its website.

A single high reading is not enough. The NHS says that if a clinic test shows you might have high blood pressure you may be asked to use a monitor at home for a few days, return to the surgery for another check, or wear a portable monitor that takes readings over 24 hours. NICE CKS says hypertension should be suspected when clinic blood pressure is sustained at or above 140/90 mmHg, and confirmed with ambulatory (ABPM) or home monitoring (HBPM).

NICE CKS grades severity. Stage 1 is a clinic reading from 140/90 to 159/99 with an ABPM or home average from 135/85 to 149/94; Stage 2 is a clinic reading of 160/100 or higher but below 180/120, with an average of 150/95 or higher; and Stage 3 (severe) is a clinic systolic of 180 or higher or diastolic of 120 or higher. While confirmation is awaited, the same source says people should be offered investigations for organ damage and secondary causes, and an assessment of cardiovascular risk.

"White-coat" hypertension, where readings are raised only in the consulting room, is one reason out-of-clinic measurements matter, and has its own guide on this site.

The NHS lists a healthy balanced diet, at least 150 minutes of exercise a week, weight loss if overweight, not eating too much salt, not drinking more than 14 units of alcohol a week on a regular basis, limiting caffeine and not smoking. NICE CKS describes management as lifestyle advice, considering drug treatment in a stepwise way, considering a statin after a cardiovascular risk assessment, and an annual review.

On medicines the NHS says there are many types, that the one recommended depends on factors such as how high the blood pressure is, your age and your ethnicity, that most are taken as a once-daily tablet and that more than one may be needed. NICE CKS lists the classes: ACE inhibitors, angiotensin-II receptor blockers, thiazide-like diuretics, calcium-channel blockers, spironolactone, beta-blockers and alpha-blockers. Medicines are informational here; choice and dose are a prescriber's decision, and tablets should not be stopped abruptly without advice.

For targets, NICE CKS gives a clinic reading below 140/90 (home or ABPM below 135/85) for people under 80, and a clinic reading below 150/90 (home or ABPM below 145/85) for those aged 80 and over, with clinical judgement for frailty or multiple conditions.

The NHS lists age, close relatives with high blood pressure, a Black African, Black Caribbean or South Asian ethnic background, a diet high in salt, being overweight, smoking, drinking too much alcohol and long periods of stress as things that increase the chance of high blood pressure. Several of these are fixed; others can be changed.

In practice a combination is usual. That is why a GP or nurse will often discuss weight, salt, alcohol, activity and smoking at the same appointment as the reading itself, and why the NHS describes healthy lifestyle changes as part of the first approach.

The NHS says to get help from NHS 111 if you often have headaches or blurred vision, have chest pain that comes and goes, or have other symptoms you are worried could be caused by high blood pressure. It says to call 999 for sudden chest pain or discomfort that does not go away, pain spreading to the arm, neck, jaw, stomach or back, or chest pain with sweating, sickness, light-headedness or breathlessness, as these could be a heart attack.

NICE CKS advises same-day specialist assessment for a clinic reading of 180/120 or higher with signs of retinal bleeding or swelling of the optic nerve, or with life-threatening symptoms such as new confusion, chest pain, signs of heart failure or acute kidney injury. A high home reading without symptoms is a different situation from these, but it is still worth reporting to the practice rather than ignoring.

Hypertension is generally a long-term condition managed rather than cured. Treatment is aimed at lowering the risk of the complications the NHS lists, and the NHS notes that even a small reduction helps. Annual reviews, repeat checks after any change in medicines, and attention to kidney function and cholesterol are the usual pattern, which NICE CKS summarises as monitoring response and reviewing annually.

Practical habits make a difference: keeping a log if you check at home, taking tablets at the same time each day, and telling the practice about side effects before stopping anything. A separate guide on this site covers side effects of blood pressure medicines and home monitoring.

Essential hypertension is almost entirely managed in general practice and community pharmacy: checks, home or ambulatory monitoring, investigations for organ damage, and prescribing. Referral to a hypertension or cardiology clinic is typically for severe or hard-to-control readings, suspected secondary causes or younger age at diagnosis, which NICE CKS suggests considering for adults under 40.

Some people choose a private cardiology or hypertension appointment for quicker ambulatory monitoring or a longer discussion of risk. The tests and treatment options are broadly the same, so the main difference is access and appointment time. It is sensible to bring home readings and a medicine list to either setting.