What is high blood pressure?

Blood pressure is the force of blood as it moves through the blood vessels. If blood cannot flow easily through the vessels, the force increases. If the force is too great, you have high blood pressure.

High blood pressure is a serious disease. It increases the workload on the heart and blood vessels and can lead to heart disease, stroke, kidney problems and even blindness.

The medical term for high blood pressure is hypertension. High blood pressure is dangerous because it makes the heart work too hard and contributes to atherosclerosis (hardening of the arteries). It increases the risk of heart disease and stroke, the first and third leading causes of death among Americans.

How can I tell if I have high blood pressure?

High blood pressure usually has no symptoms. In fact, many people have high blood pressure for years without knowing it. That's why it's called the "silent killer". In 90-95 percent of cases, the cause of high blood pressure is unknown.

A single elevated blood pressure reading doesn't mean you have high blood pressure, but it's a sign that further observation is required. The only way to find out if you have high blood pressure is to have your blood pressure checked.

Who is affected?

High blood pressure affects about 50 million (or one in four) American adults. It is especially common among African Americans, who tend to develop it earlier and more often than whites. Also, many Americans tend to develop high blood pressure as they get older; however hypertension is not a part of healthy aging. About 60 percent of all Americans age 60 and older have high blood pressure.

Others at high risk of developing hypertension are persons who are overweight, those with a family history of high blood pressure, and those with a high-normal blood pressure.

Does smoking tobacco cause high blood pressure?

No. However, it can temporarily raise blood pressure, and it does increase the risk of heart and blood vessel diseases. Smoking injures blood vessel walls and speeds up the process of hardening of the arteries. If you smoke, quit. Your risk of having a heart attack is reduced after the first year.

What do blood pressure numbers indicate?

The higher (systolic) number represents the pressure while the heart is beating.

The lower (diastolic) number represents the pressure when the heart is resting between beats.

The systolic pressure is always stated first and the diastolic pressure second. For example; if a person's blood pressure is 122/76 (122 over 76), the systolic pressure is 122 and the diastolic pressure is 76.

Categories for blood pressure levels in adults*
(Ages 18 Years and Older)

  Blood Pressure Level (mm Hg)  
Category Systolic Diastolic
Normal <120 and <80
Prehypertension 120-139 or 80-89
Hypertension, Stage 1 140-159 or 90-99
Hypertension, Stage 2 >160 or >100

From the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of HIgh Blood Pressure (JNC7)

< means LESS THAN

How often should I have my blood pressure checked?

If you do not have high blood pressure then you should have your pressure checked at least every two years. If you have high blood pressure consult with your health care provider.

What are Factors that contribute to high blood pressure?

Because medical science doesn't understand why most cases of high blood pressure occur, it's hard to say how to prevent it. However, we do know of several factors that may contribute to high blood pressure and put you at risk for heart attack and stroke.

Controllable risk factors?

Obesity - People with a body mass index (BMI)* of 30.0 or higher are more likely to develop high blood pressure.

Eating too much salt - This increases blood much salt pressure in some people.

Alcohol - Heavy and regular use of alcohol can increase blood pressure dramatically.

Lack of exercise - An inactive lifestyle makes it exercise easier to become overweight and increases the chance of high blood pressure.

Stress - This is often mentioned as a risk factor. However, stress levels are hard to measure, and responses to stress vary from person to person.

What are uncontrollable risk factors?

Race - African Americans develop high blood pressure more often than whites, and it tends to occur earlier and be more severe.

Heredity - A tendency to have high blood pressure runs in families. If your parents or other close blood relatives have it, you're more likely to develop it.

Age - In general, the older you get, the greater your chance of developing high blood pressure. It occurs most often in people over age 35. Men seem to develop it most often between age 35 and 50. Women are more likely to develop it after menopause.

*BMI (body mass index) is used to define nutritional status and is derived from the following formula:

BMI=703 x Body Weight ÷ (Height ix Height) (in pounds) (in inches)

The standards are the same for men and women. A BMI of 25 to 29.9 is considered overweight.

Source: American Heart Association National Heart, Lung, and Blood Institute

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