Blood pressure is the force exerted by the blood against the walls of the blood vessels. The pressure depends on the work being done by the heart and the resistance of the blood vessels.
Medical guidelines define hypertension as a blood pressure higher than 130 over 80 millimeters of mercury (mmHg), according to guidelines issued by the American Heart Association (AHA) in November 2017.
Hypertension and heart disease are global health concerns. The World Health Organization (WHO) suggests that the growth of the processed food industry has impacted the amount of salt in diets worldwide, and that this plays a role in hypertension.
Here are some key points about hypertension. More detail is in the main article.
- Normal blood pressure is 120 over 80 mm of mercury (mmHg), but hypertension is higher than 130 over 80 mmHg.
- Acute causes of high blood pressure include stress, but it can happen on its own, or it can result from an underlying condition, such as kidney disease.
- Unmanaged hypertension can lead to a heart attack, stroke, and other problems.
- Lifestyle factors are the best way to address high blood pressure.
Regular health checks are the best way to monitor your blood pressure.
While blood pressure is best regulated through the diet before it reaches the stage of hypertension, there is a range of treatment options.
Lifestyle adjustments are the standard first-line treatment for hypertension.
Regular physical exercise
Doctors recommend that patients with hypertension engage in 30 minutes of moderate-intensity, dynamic, aerobic exercise. This can include walking, jogging, cycling, or swimming on 5 to 7 days of the week.
Avoiding stress, or developing strategies for managing unavoidable stress, can help with blood pressure control.
Using alcohol, drugs, smoking, and unhealthy eating to cope with stress will add to hypertensive problems. These should be avoided.
Smoking can raise blood pressure. Giving up smoking reduces the risk of hypertension, heart conditions, and other health issues.
People with blood pressure higher than 130 over 80 may use medication to treat hypertension.
Drugs are usually started one at a time at a low dose. Side effects associated with antihypertensive drugs are usually minor.
Eventually, a combination of at least two antihypertensive drugs is usually required.
A range of drug types are available to help lower blood pressure, including:
- diuretics, including thiazides, chlorthalidone, and indapamide
- beta-blockers and alpha-blockers
- calcium-channel blockers
- central agonists
- peripheral adrenergic inhibitor
- angiotensin-converting enzyme (ACE) inhibitors
- angiotensin receptor blockers
The choice of drug depends on the individual and any other conditions they may have.
Anyone taking antihypertensive medications should be sure to carefully read labels, especially before taking any over-the-counter (OTC) medications, such as decongestants.
These may interact with medications used to lower blood pressure.
The cause of hypertension is often not known.
Around 1 in every 20 cases of hypertension is the effect of an underlying condition or medication.
Chronic kidney disease (CKD) is a common cause of high blood pressure because the kidneys do not filter out fluid. This fluid excess leads to hypertension.
A number of risk factors increase the chances of having hypertension.
- Age: Hypertension is more common in people aged over 60 years. With age, blood pressure can increase steadily as the arteries become stiffer and narrower due to plaque build-up.
- Ethnicity: Some ethnic groups are more prone to hypertension.
- Size and weight: Being overweight or obese is a key risk factor.
- Alcohol and tobacco use: Consuming large amounts of alcohol regularly can increase a person's blood pressure, as can smoking tobacco.
- Sex: The lifetime risk is the same for males and females, but men are more prone to hypertension at a younger age. The prevalence tends to be higher in older women.
- Existing health conditions: Cardiovascular disease, diabetes, chronic kidney disease, and high cholesterol levels can lead to hypertension, especially as people get older.
Other contributing factors include:
- physical inactivity
- a salt-rich diet associated with processed and fatty foods
- low potassium in the diet
- alcohol and tobacco use
- certain diseases and medications
A family history of high blood pressure and poorly managed stress can also contribute.
Blood pressure can be measured by a sphygmomanometer, or blood pressure monitor.
Having high blood pressure for a short time can be a normal response to many situations. Acute stress and intense exercise, for example, can briefly elevate blood pressure in a healthy person.
For this reason, a diagnosis of hypertension normally requires several readings that show high blood pressure over time.
The systolic reading of 130 mmHg refers to the pressure as the heart pumps blood around the body. The diastolic reading of 80 mmHg refers to the pressure as the heart relaxes and refills with blood.
The AHA 2017 guidelines define the following ranges of blood pressure:
Normal blood pressure
Less than 120
Less than 80
Between 120 and 129
Less than 80
Stage 1 hypertension
Between 130 and 139
Between 80 and 89
Stage 2 hypertension
At least 140
At least 90
If the reading shows a hypertensive crisis when taking blood pressure, wait 2 or 3 minutes and then repeat the test.
If the reading is the same or higher, this is a medical emergency.
The person should seek immediate attention at the nearest hospital.
A person with hypertension may not notice any symptoms, and it is often called the "silent killer." While undetected, it can cause damage to the cardiovascular system and internal organs, such as the kidneys.
Regularly checking your blood pressure is vital, as there will usually be no symptoms to make you aware of the condition.
If blood pressure reaches the level of a hypertensive crisis, a person may experience headaches and nosebleeds.
Long-term hypertension can cause complications through atherosclerosis, where the formation of plaque results in the narrowing of blood vessels. This makes hypertension worse, as the heart must pump harder to deliver blood to the body.
High blood pressure raises the risk of a number of health problems, including a heart attack.
Hypertension-related atherosclerosis can lead to:
- heart failure and heart attacks
- an aneurysm, or an abnormal bulge in the wall of an artery that can burst, causing severe bleeding and, in some cases, death
- kidney failure
- hypertensive retinopathies in the eye, which can lead to blindness
Regular blood pressure testing can help people avoid the more severe complications.
Some types of hypertension can be managed through lifestyle and dietary choices, such as engaging in physical activity, reducing alcohol and tobacco use, and avoiding a high-sodium diet.
Reducing the amount of salt
Average salt intake is between 9 grams (g) and 12 g per day in most countries around the world.
The WHO recommends reducing intake to under 5 g a day, to help decrease the risk of hypertension and related health problems.
This can benefit people both with and without hypertension, but those with high blood pressure will benefit the most.
Moderating alcohol consumption
Moderate to excessive alcohol consumption is linked to raised blood pressure and an increased risk of stroke.
The American Heart Association (AHA) recommend a maximum of two drinks a day for men, and one for women.
The following would count as one drink:
- 12 ounce (oz.) bottle of beer
- 4 oz. of wine
- 1.5 oz. of 80-proof spirits
- 1 oz. of 100-proof spirits
A healthcare provider can help people who find it difficult to cut back.
Eating more fruit and vegetables and less fat
People who have or who are at risk of high blood pressure are advised to eat as little saturated and total fat as possible.
Recommended instead are:
- whole-grain, high-fiber foods
- a variety of fruit and vegetables
- beans, pulses, and nuts
- omega-3-rich fish twice a week
- non-tropical vegetable oils, for example, olive oil
- skinless poultry and fish
- low-fat dairy products
It is important to avoid trans-fats, hydrogenated vegetable oils, and animal fats, and to eat portions of moderate size.
Managing body weight
Hypertension is closely related to excess body weight, and weight reduction is normally followed by a fall in blood pressure. A healthy, balanced diet with a calorie intake that matches the individual's size, sex, and activity level will help.
The DASH diet
The U.S. National Heart Lung and Blood Institute (NHLBI) recommends the DASH diet for people with high blood pressure. DASH, or "Dietary Approaches to Stop Hypertension," has been specially designed to help people lower their blood pressure.
It is a flexible and balanced eating plan based on research studies sponsored by the Institute, which says that the diet:
- lowers high blood pressure
- improves levels of fats in the bloodstream
- reduces the risk of developing cardiovascular disease
There is a cookbook written by the NHLBI called Keep the Beat Recipes with cooking ideas to help achieve these results.
Some evidence suggests that using probiotic supplements for 8 weeks or more may benefit people with hypertension.
High blood pressure that is not caused by another condition or disease is called primary or essential hypertension. If it occurs as a result of another condition, it is called secondary hypertension.
Primary hypertension can result from multiple factors, including blood plasma volume and activity of the hormones that regulate of blood volume and pressure. It is also influenced by environmental factors, such as stress and lack of exercise.
Secondary hypertension has specific causes and is a complication of another problem.
It can result from:
- diabetes, due to both kidney problems and nerve damage
- kidney disease
- pheochromocytoma, a rare cancer of an adrenal gland
- Cushing syndrome, which can be caused by corticosteroid drugs
- congenital adrenal hyperplasia, a disorder of the cortisol-secreting adrenal glands
- hyperthyroidism, or an overactive thyroid gland
- hyperparathyroidism, which affects calcium and phosphorous levels
- sleep apnea
Treating the underlying condition should see an improvement in blood pressure.