What is hypertension (high blood pressure)?

Hypertension is defined as having a blood pressure higher than 140 over 90 mmHg, with a consensus across medical guidelines.

The number of people living with hypertension (high blood pressure) is predicted to be 1.56 billion worldwide by the year 2025.

The increasing prevalence of the condition is blamed on lifestyle and dietary factors, such as physical inactivity, alcohol and tobacco use, and a diet high in sodium (usually from processed and fatty foods).

Fast facts on hypertension

Here are some key points about hypertension. More detail and supporting information is in the body of this article.

§ Hypertension is defined as blood pressure higher than 140 over 90 mmHg (millimeters of mercury).

§ A diagnosis of hypertension may be made when one or both readings are high: systolic (the pressure as the heart pumps blood around the body), given first; or diastolic (pressure as the heart relaxes and refills with blood), given second.

§ Modern lifestyle factors are responsible for a growing burden of hypertension: physical inactivity, salt-rich diets with processed and fatty foods, and alcohol and tobacco use.

§ High blood pressure can also be secondary to other conditions - kidney disease, for example - and can be associated with some medications.

§ Hypertension itself does not cause symptoms but in the long-term leads to complications caused by narrowing of blood vessels.

§ Doctors diagnose high blood pressure over a number of visits using a sphygmomanometer, which involves applying an inflatable cuff to the upper arm.

§ Lifestyle measures are used first to treat high blood pressure, including salt restriction and other dietary changes, moderation of alcohol, and stress reduction.

§ One or more drugs from a number of different classes may be used for treatment.

Causes of hypertension

As acute stress, intense exercise and other factors can briefly elevate blood pressure even in people whose blood pressure is normal, a diagnosis of hypertension requires several readings showing high blood pressure over time. 

Having high blood pressure for a short amount of time is a normal physiological response to many situations. However, a systolic reading of 180 mmHg or higher OR a diastolic reading of 110 mmHG or higher could be a sign of a hypertensive crisis that warrants immediate medical attention.

Blood pressure does vary throughout the day, lowering during sleep and rising on awakening. It also rises in response to excitement, anxiety and physical activity.

Blood pressure also increases steadily with age as arteries become stiffer and narrower due to plaque build-up. Vascular and heart disease also contribute to rising blood pressure in older adults, and a high systolic reading is a major risk factor for cardiovascular disease in adults over 50 years old. Other key contributors include lifestyle factors, such as:

§  Physical inactivity

§  A salt-rich diet associated with processed and fatty foods

§  Alcohol and tobacco use.

Certain diseases and medications (as described below) can cause 

high blood pressure, and there are a number of general risk factors 

for hypertension, including:

§  Age - everyone is at greater risk of high blood pressure as they get older. Prevalence of hypertension is higher in people over 60 years of age

§  Race - African-American adults are at higher risk than white or Hispanic American adults

§  Size - being overweight or obese is a key risk factor for hypertension

§  Sex - males and females have different risk profiles. While lifetime risk is the same for everybody, men are more prone to hypertension at a younger age and women have a higher rate of hypertension at older ages

§  Lifestyle - greater intake of dietary salt, excessive alcohol, low dietary potassium, and physical inactivity all contribute to an increased risk of hypertension.

Other risk factors include a family history of the disease, and chronic, poorly managed stress.

Symptoms of hypertension

High blood pressure itself is usually asymptomatic, meaning that patients do not experience any direct symptoms of the condition. This is why hypertension is often referred to as "the silent killer," as it can quietly causes damage to the cardiovascular system.

Hypertension can also lead to problems in the organs affected by high blood pressure. Long-term hypertension can cause complications through arteriosclerosis, where the formation of plaques results in narrowing of blood vessels.

The complications associated with hypertension-related arteriosclerosis can include:

§  An enlarged or weakened heart, to a point where it may fail to pump enough blood (heart failure)

§  Aneurysm - an abnormal bulge in the wall of an artery (which can burst, causing severe bleeding and, in some cases, death)

§  Blood vessel narrowing - in the kidneys this can lead to possible kidney failure; in the heart, brain and legs, this can lead to heart attack, stroke or the need for amputation, respectively

§  Blood vessels in the eyes my rupture or bleed, leading to vision problems or blindness (hypertensive retinopathies - classified by worsening grades one through four).

Ways to Prevent Hypertension

Making an effort to prevent high blood pressure can reduce your risk of heart attack, stroke, and other serious illnesses. If you are at risk for hypertension, take these steps to help prevent it.

1. Maintain a healthy weight. When it comes to hypertension prevention, your weight is crucial, says Dr. Ogedegbe. People who are overweight should try to lose weight, and people of normal weight should avoid adding on any pounds. If you are carrying extra weight, losing as little as 10 pounds can help prevent high blood pressure. Talk with your doctor about the best weight for you.
2. Eat a balanced diet. Eating healthful foods can help keep your blood pressure under control. Get plenty of fruits and vegetables, especially those rich in potassium, and limit your intake of excess calories, fat, and sugar. Consider following the Dietary Approaches to Stop Hypertension, or DASH, diet, which has been shown to help manage blood pressure.
3. Cut back on salt. For many people, eating a low-sodium diet can help keep blood pressure normal. "The higher the sodium intake, the higher the blood pressure," says Ogedegbe. You can cut back on your total salt intake by avoiding high-sodium packaged and processed foods and not adding extra salt to your meals. "I tell people to stay away from salt shakers," adds Ogedegbe
4. Exercise regularly. Get moving to prevent hypertension. Physical activity is crucial. The more exercise you get, the better, but even a little bit can help control blood pressure. Moderate exercise for about 30 minutes three times a week is a good start.
5. Limit the alcohol. Drinking too much alcohol can lead to high blood pressure. For women, that means no more than one drink a day, and for men, no more than.
6. Monitor your blood pressure. Make sure that you have your blood pressure measured regularly, either at your doctor's office or at home. High blood pressure often occurs with no symptoms, so only blood pressure readings will tell you if your blood pressure is on the rise. If your doctor determines that you have prehypertension — blood pressure in the range of 120-139/80-89 millimeters of mercury (mmHg) that puts you at increased risk of developing hypertension — your doctor may recommend extra steps as a safeguard.
7. Take a look at your lifestyle habits and decide where you can make changes to help prevent hypertension. Conquer small goals, such as snacking on fruits and vegetables instead of junk food, and continue to practice these good habits until they are a part of your daily routine.
   Adopting these lifestyle changes can help prevent high blood pressure if your blood pressure is currently under control or lead to lower blood pressure if your numbers are already elevated.