What is blood pressure?
With each beat of the heart, blood is pumped out of the heart into the blood vessels, which carry your blood throughout your body. Your blood pressure is a measurement of the pressure or force inside your arteries with each heartbeat.
How is blood pressure measured?
Your doctor or health care provider can check your blood pressure during a physical exam. (You can also check your own blood pressure at home.) Blood pressure is measured with a device known as a sphygmomanometer, which consists of a stethoscope, arm cuff, dial, pump, and valve. (A digital blood pressure monitor provides an electronic blood pressure reading.)
Your blood pressure is measured in the following manner:
- The cuff is wrapped over your arm and inflated with the pump until it stops the flow of blood.
- The valve lets air out of the cuff, which starts the blood flow again.
- The stethoscope is placed under the cuff to listen for the sound of blood rushing back through the artery. It is measured as two numbers:
- Systolic blood pressure – the first number; the amount of pressure against the artery walls each time the heart contracts or squeezes blood out of your heart.
- Diastolic blood pressure – the second number; the amount of pressure inside your arteries when your heart is at rest, in between heartbeats.
Your blood pressure recording is not always the same. When you are exercising or excited, your blood pressure goes up. If you are at rest, your blood pressure will be lower. This is a normal response to changes in activity or emotion. Age, medications, and changes in position can also affect blood pressure.
What is a normal blood pressure reading?
To decrease the risk of cardiovascular (heart and blood vessel) disease, normal blood pressure, for those not taking blood pressure medications, should be less than 120/80.
What is high blood pressure?
High blood pressure is also called hypertension.
- One in three American adults has hypertension, this represents about 50 million people. Up to half of them don’t know it until they suffer a stroke or myocardial infarction (heart attacks). This is why hypertension is known as the "silent killer."
- 34 million adults have high normal blood pressure. At least 1/3 of all heart attacks and strokes occur in people with high normal blood pressures.
- Fewer than half of all Americans have ideal blood pressures.
How does your blood pressure measure up?
|Blood Pressure Classifications ||Range (mm/hg) ||Therapy? |
|Patients with chronic renal disease or diabetes should be treated to less than 130/80* |
|While, 120/80 is optimal blood pressure, if you have been diagnosed with high blood pressure, the goal is to lower your blood pressure to less than 140/80. |
|JNC VII, National Heart, Lung, and Blood Institute, - 2003. |
|Normal blood pressure* ||less than 120/80 ||Encourage healthy lifestyle |
|Pre-hypertension ||120 to 139/80-89 ||Modify lifestyle |
|Hypertension: || || |
|Stage 1 ||140 to 159/90-99 ||Modify Lifestyle |
|Stage 2 ||greater or equal to 160/ greater to or equal to 100 ||Modify Lifestyle |
The diagnosis of high blood pressure should be confirmed on at least three visits, one to several weeks apart. During your exam, you should be seated for at least five minutes in a chair, with feet on the floor, and arm supported at heart level. Do not smoke or drink caffeine within 30 minutes before your measurement to insure the best results.
A note about blood pressure monitors
Some people get nervous when they go to their doctor. This causes blood pressure to rise and is called "white coat syndrome." To confirm if your blood pressure is high at other times, you may be asked to:
- Purchase a blood pressure monitor. You will be asked to check your blood pressure at different times of the day and keep a record. You can bring this record with you at your appointments. Find more information on blood pressure monitors.
- Wear a blood pressure monitor. This monitor is attached to you. You will be asked to wear it for 24 hours. The monitor is usually programmed to take blood pressure readings every 15 to 30 minutes all day and night while you go about your normal activities. The doctor will evaluate the results.
Home blood pressure monitors may also be used to monitor the effectiveness of your treatment.
Why do I need to treat high blood pressure?
High blood pressure is a major risk factor for heart and blood vessel disease. If untreated, it can lead to:
- Transient ischemic attack (TIA) or stroke
- Heart attack
- Heart enlargement
- Heart failure
- Peripheral vascular disease, such as lack of blood circulation in the legs, claudication, or aneurysms
- Kidney disease
- Hemorrhages in the blood vessels in the eyes
Are you at risk for getting high blood pressure?
High blood pressure is more common in:
- People with family members who have a history of high blood pressure, cardiovascular disease or diabetes
- African Americans
- People 60 years and older
- Women who take oral contraceptives
- People who are overweight
What should you do if you have high blood pressure?
The goal of therapy is to lower your blood pressure to less than 120/80. If you have diabetes or chronic kidney disease, the goal is less than 130/80. If you have high blood pressure:
- Eat a diet low in sodium (salt) and fat
- Maintain your ideal body weight
- Quit smoking
- Follow a regular exercise program
- Limit alcohol intake to no more than 1 drink per day
- Take your blood pressure medications as directed
- Have regular blood pressure checks to see your progress.
- Keeping the Heart Healthy, In (E. Topol, ed.) Cleveland Clinic Heart Book, Hyperion: New York. pp.19-43.
- Joint National Committee on Detection, Evaluation and Treatment of Blood Pressure. The Seventh Report of the Joint National Committee on Detection, Evaluation and Treatment of Blood Pressure, National Heart, Lung, and Blood Institute*, 2003.
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