Hypertension (High Blood Pressure)
On this page:
- What is blood pressure?
- How is blood pressure measured?
- High blood pressure (hypertension)
- Prehypertension
- Categories and ranges in adults
- Treatment
- Risk factors and prevention
- For more information
What is blood pressure? Blood pressure is the force of blood against the walls of the arteries. The heart creates this force as it contracts and as it rests between contractions.
Blood pressure goes up and down depending on what you are doing. It may rise during periods of excitement, nervousness, or exercise and decrease during sleep.
Some people experience "white coat hypertension", when their blood pressure is elevated because of the anxiety of seeing a clinician. In this case, it is recommended that you have a series of blood pressure readings outside of the clinical setting to determine if you are truly hypertensive.
How is blood pressure measured? Blood pressure incorporates two measures:
Systolic blood pressure is the pressure against artery walls as the heart contracts (or beats) and pushes blood into the arteries. This is the top or first number in a blood pressure reading.
Diastolic blood pressure is the pressure against artery walls between heart contractions. This is the bottom or second number in a blood pressure reading.
High blood pressure (hypertension) exists if the systolic number or the diastolic number stays higher than normal most of the time (see Categories and Ranges in Adults). The heart has to pump harder to move blood through the body, adding to the workload of the heart and blood vessels.
High blood pressure can damage the blood vessels and heart, increasing the risk of stroke, heart disease (including heart attack) and kidney disease.
Individuals in the early stages of high blood pressure generally have no symptoms or specific warning signals. Contrary to popular belief, headaches or nosebleeds are not usually symptoms of the early stages of high blood pressure. The only reliable way to know if you have or are developing high blood pressure is to have it checked.
Prehypertension is a high-risk precursor to hypertension (see Categories and Ranges in Adults). Adults with prehypertension are twice as likely to progress to hypertension than adults with lower blood pressure. If you are diagnosed with prehypertension, you should have annual blood pressure checks, and your clinician can counsel you about Risk Factors and Prevention.
Categories and Ranges in Adults
|
Blood Pressure
(mm Hg - millimeters of mercury) |
||
| Category |
Systolic
|
Diastolic
|
| Normal |
<120
|
<80
|
| Prehypertension |
120-139
|
80-89*
|
| Stage 1 Hypertension |
140-159
|
90-99
|
| Stage 2 Hypertension |
≥ 160
|
≥ 100
|
*Individuals with diabetes or kidney disease should try to keep their blood pressure at or below 130/80 because they are at higher risk for the consequences of hypertension.
Treatment: High blood pressure usually cannot be cured, but it can be controlled with proper treatment. See also Risk Factors and Prevention. Controlling high blood pressure can help prevent heart disease, kidney disease and stroke. However, it usually requires lifelong medication for those individuals whose blood pressure is definitely abnormal.
If your clinician prescribes one or more medications for you, it is important that you take them regularly (not just when you remember it or feel bad).
There are different types of high blood pressure medications. Your clinician will determine which is the most appropriate for you. Different medications have various side effects, which may include frequent urination, dry mouth, or a change in energy level or sexual libido. Discuss side effects with your clinician, because many can be prevented by a change in medication dosage or type.
Risk Factors and Prevention: In most cases, actual causes of high blood pressure are unknown. However, the following risk factors are established as contributing to high blood pressure.
Smoking tobacco is the single worst thing that one can do to one's health, especially for persons with high blood pressure. Nicotine constricts blood vessels, stimulates the heart and increases the rate at which fatty deposits occur within the arteries. This can increase the destruction of the arteries already caused by high blood pressure. If you smoke, quit. See Tobacco: You Can Quit!
Being overweight can increase your blood pressure. With each extra pound, the body must increase blood volume and the number of capillaries to supply the fatty tissue. This means that the heart must work harder. Losing weight can lessen this strain on the heart. Restricting cholesterol and saturated fat may diminish the build-up in the inner lining of the blood vessels. Maintaining a healthy weight permanently requires a change in eating habits, exercise patterns and attitudes. For more, see Weight Reduction.
Excessive sodium intake (mostly as table salt or food additives) may be detrimental to individuals who are sensitive to sodium or who have a history of high blood pressure. These individuals should examine food labels carefully, avoid salty and processed foods and use herbs and seasonings for flavor rather than salt.
Lack of exercise: Regular physical exercise may decrease the rate of fatty deposit build-up on the artery walls, strengthen the heart and reduce heart rate and blood pressure. Physical activity that is rhythmic and repetitive (such as brisk walking, jogging, bicycling, swimming, cross country skiing and jumping rope) are best for building cardiovascular fitness. For more information, see Exercise.
Alcohol: Studies have shown that consumption of as little as two drinks a day can have a harmful affect on blood pressure.
Genetics: Blood pressure levels are correlated among families. This can be attributed to genetics, shared environment or lifestyle factors. If either or both of your parents have high blood pressure, you are at greater risk of developing it, so get your blood pressure checked.
To visit a UHS clinician, Schedule an Appointment.
WebMD Frequently Asked Questions about Hypertension
See a tutorial about hypertension from MedlinePlus
