Hypertension (High Blood Pressure)

What hypertension is

Each heartbeat pushes blood into the arteries. Blood pressure depends on how much blood the heart pumps and how much resistance the arteries offer. In hypertension, the arteries are stiffer or narrower, or the body holds too much salt and water, so pressure stays high.

Constant high pressure injures the inner lining of the arteries, speeds up the build-up of fatty plaque (atherosclerosis), and makes the heart work harder. Organs with many small blood vessels, such as the brain, kidneys and eyes, are particularly vulnerable.

If you have just had a high reading and want to know what to do now, see high blood pressure reading: symptoms and what to do.

Stages of hypertension

UK and European guidelines define hypertension as 140/90 or higher in the clinic, or 135/85 or higher on home readings. Both approaches agree that risk rises steadily as pressure rises, starting from about 115/75.

Other patterns:

• Isolated systolic hypertension: only the top number is high. It is common in older adults because arteries stiffen with age.
• White coat hypertension: high in the clinic, normal at home.
• Masked hypertension: normal in the clinic, high at home. It carries similar risks to sustained hypertension.
• Resistant hypertension: above target despite 3 medicines at good doses, including a diuretic.

Causes and risk factors

Primary (essential) hypertension

About 90 to 95% of adults have primary hypertension, which develops gradually from a mix of genes, age and lifestyle:

• Age: blood pressure rises as arteries stiffen.
• Family history.
• Race: Black adults in the US develop hypertension more often, earlier and more severely.
• Excess weight: the strongest modifiable risk factor.
• High salt intake, low potassium intake.
• Physical inactivity.
• Alcohol: more than 1 drink a day for women or 2 for men.
• Smoking, which causes temporary spikes and damages arteries.
• Chronic stress and poor sleep.
• Diabetes and high cholesterol, which often occur together with hypertension.

Secondary hypertension

A specific cause is found in about 5 to 10% of people. Suspect it if hypertension starts before 30, is severe or suddenly worse, or resists treatment:

• Chronic kidney disease and renal artery stenosis
• Obstructive sleep apnea: very common in resistant hypertension
• Primary aldosteronism: an adrenal hormone excess, sometimes with low potassium
• Thyroid disease, Cushing syndrome and pheochromocytoma
• Coarctation of the aorta: narrowing of the main artery, in children and young adults
• Medicines and substances: NSAIDs, decongestants, steroids, estrogen-containing birth control, some antidepressants, stimulants, cocaine, licorice
• Pregnancy-related hypertension and preeclampsia

Symptoms

Most people have no symptoms. Hypertension is often found at a routine visit or only after a complication. Very high blood pressure can cause headaches, blurred vision, nosebleeds, chest pain and breathlessness, which need urgent care.

Diagnosis

1. Repeated measurement: at least 2 readings on 2 or more occasions.
2. Out-of-office confirmation: home monitoring over a week, or 24-hour ambulatory monitoring, which is the most accurate method.
3. Baseline tests: blood count, sodium, potassium, kidney function, glucose or HbA1c, cholesterol, thyroid function, a urine test for protein, and an ECG.
4. Risk assessment: your 10-year risk of heart attack and stroke guides how quickly to start medicines.
5. Tests for secondary causes when suspected: renin and aldosterone, kidney ultrasound, sleep study and others.

Treatment

The general goal for most adults is a blood pressure below 130/80. Targets may be individualized for older or frail people.

Lifestyle changes

Each of these lowers systolic pressure by roughly 4 to 11 mmHg, and their effects add up:

• DASH-style diet: vegetables, fruit, whole grains, low-fat dairy, nuts and beans, with less red meat and sugar.
• Less sodium: aim for under 1,500 mg a day, or at least 1,000 mg less than now. Most salt comes from bread, processed meat, soups, sauces and restaurant food.
• More potassium from food, such as beans, potatoes, bananas and leafy greens, unless you have kidney disease.
• Weight loss: about 1 mmHg for every 1 kg (2.2 lb) lost.
• Exercise: 150 minutes a week of moderate aerobic activity, plus resistance training.
• Limit alcohol and stop smoking.
• Sleep: treat sleep apnea and aim for 7 to 9 hours.

Medicines

Medicines are recommended for stage 2 hypertension, and for stage 1 with high cardiovascular risk, diabetes or kidney disease. The main first-line classes are:

Many people need 2 or more medicines, often combined in one pill. Beta-blockers are used when there is another reason, such as heart failure or a previous heart attack. ACE inhibitors and ARBs must not be used in pregnancy.

Monitoring

Home monitoring with a validated upper-arm cuff helps adjust treatment. After starting or changing medicine, follow-up is usually within a month until blood pressure is controlled.

Complications

• Stroke and vascular dementia
• Heart attack and coronary artery disease
• Heart failure and thickening of the heart muscle (hypertensive heart disease)
• Atrial fibrillation
• Kidney disease, which can progress to kidney failure
• Eye damage (hypertensive retinopathy)
• Aortic aneurysm and dissection
• Peripheral artery disease
• Erectile dysfunction

Lowering systolic blood pressure by 10 mmHg reduces the risk of major cardiovascular events by about 20% and stroke by about 27%, according to large analyses of clinical trials.

Living with hypertension

Hypertension is usually lifelong, but it is very controllable. Take medicines every day even when you feel well, check your readings at home, and review side effects with your doctor rather than stopping medicines. Avoid NSAIDs and decongestants unless your doctor approves them. Women planning pregnancy should discuss medicine changes beforehand.

Prevention

The same habits that treat hypertension help prevent it: a healthy weight, regular exercise, low salt, a diet rich in vegetables and fruit, limited alcohol and no smoking. Adults should have their blood pressure checked at least every year from age 40, and every 3 to 5 years from age 18 if readings are normal.

Frequently asked questions

What causes hypertension?

Most hypertension has no single cause. It develops from a combination of age, genes, excess weight, high salt intake, inactivity and alcohol. In about 5 to 10% of people, a specific cause is found, such as kidney disease, sleep apnea, hormone disorders or medicines.

What is the difference between primary and secondary hypertension?

Primary (essential) hypertension develops gradually without one identifiable cause and accounts for most cases. Secondary hypertension is caused by another condition or medicine, such as kidney disease, primary aldosteronism, sleep apnea or decongestants. Treating the cause can lower or cure secondary hypertension.

Can hypertension be cured?

Primary hypertension usually cannot be cured, but it can be controlled long term with lifestyle changes and medicine. Some people who lose weight, cut salt and alcohol, and exercise can reduce or stop medicines under supervision. Secondary hypertension may resolve once its cause is treated.

How quickly can I lower my blood pressure naturally?

Cutting salt and alcohol can lower blood pressure within a few weeks. Regular exercise shows benefit within 1 to 3 months. Weight loss lowers it gradually, by about 1 mmHg per kilogram lost. Many people still need medicine to reach their target.

Do I need to take blood pressure medicine for life?

Often, yes, because hypertension is a long-term condition. Stopping medicine usually lets blood pressure rise again. If you make major lifestyle changes, your doctor may lower the dose or stop a medicine, with close monitoring. Never stop on your own.

Is 140/90 high blood pressure?

Yes. A reading of 140/90 is stage 2 hypertension under US guidelines and the threshold for hypertension in clinic readings under UK and European guidelines. One reading is not a diagnosis. Repeat measurements and home monitoring confirm it.