No medical checkup is complete without getting your blood pressure measured. Pressure that stays too high for too long can damage blood vessels and greatly increase your risk of a heart attack, a stroke, or kidney damage. On the bright side, this simple test can give you the information you need to help prevent and control high blood pressure.
What do the numbers mean?
When you check your pressure, you'll end up with two numbers, something like 130/80. The top number, called the systolic, describes the force of your blood when your heart beats. The bottom number, or diastolic, is the pressure when the main chamber in the left ventricle of your heart is at rest.
There's no single cut-off between healthy and unhealthy blood pressure. The American Heart Association (AHA) and the National Heart, Lung, and Blood Institute identify "prehypertension" as blood pressure that falls between 120-139/80-89. And, as a general guideline, 140/90 or higher qualifies as high blood pressure, or hypertension. The AHA then breaks high blood pressure up into two stages: Stage 1 is 140-159/90-99, and Stage 2 is anything 160/100 or higher. Depending on your situation, you may use yet a different benchmark. For instance, doctors urge most patients with diabetes to aim for a pressure that's less than 130/80.
Experts also disagree on the correct threshold for treatment. For example, 2013 guidelines published in the Journal of the American Medical Association recommend drug treatment for high blood pressure in people 60 and older only if the blood pressure exceeds 150/90, but the American Heart Association is firm that threshold should start at 140/90. And for people with diabetes, experts now recommend treatment for high blood pressure only when blood pressure is 140/90 or more.
Why does my child's blood pressure need to be checked?
High blood pressure isn't just a disease for older people. In recent years, a younger generation of Americans, including children in their teenage years, has seen its blood pressure rise as a growing number of them become overweight. According to a study in JAMA, the average blood pressure of American children and adolescents has risen over the last ten years, leading to a greater risk of developing hypertension later in life. Researchers blame the higher blood pressure readings on lack of exercise, poor eating habits, and excess weight.
For this reason, federal guidelines recommend blood pressure checks for children age 3 and older during routine office visits (at least yearly). A reading over the 95th percentile for the child's size and age would be considered to be hypertension, and a reading between the 90th and 95th percentile would be considered prehypertension. Doctors say that children may be able to avoid both labels by pursuing healthy lifestyles with regular exercise and a low-fat diet rich in fruits and vegetables.
Why do I need to check my blood pressure?
If you have high blood pressure, you may need to check your pressure every day, not just every time you see your doctor. Daily at-home measurements can help you track the effectiveness of your treatments. And because blood pressure can change from day to day (and even hour to hour), daily testing can give you a more accurate idea of your typical pressure.
There's another reason to check pressure at home: Many people feel a little nervous around doctors, and as a result, some have higher blood pressure in the doctor's office than they have in comfortable surroundings. This is often called "white coat hypertension," a condition that warrants further attention from your doctor. For some people, however, the only way to get an accurate picture of their blood pressure is to check themselves at home.
What do I need to check my pressure?
There are several different types of monitors for checking your blood pressure at home. The most commonly used devices have a cuff that fits around your upper arm. Others are designed to wrap around the wrist or finger. According to the American Academy of Family Physicians, home devices that measure pressure from the wrist or finger aren't as accurate as arm devices, and are not recommended.
Arm devices come in two basic types: aneroid monitors and digital monitors. Aneroid monitors are similar to the ones used in most doctors' offices. You wrap the cuff around your arm, squeeze a rubber ball to inflate the cuff, and listen to your pulse through a stethoscope as the cuff slowly deflates.
Digital monitors work in a similar way, but you don't have to use a stethoscope. Also, some models inflate automatically, so you don't have to squeeze a bulb. These are sometimes called fully automatic monitors. After the cuff deflates, your pressure appears on a screen.
Aneroid monitors are less expensive than digital monitors. As reported by the American Academy of Family Physicians, aneroid monitors generally cost $20 or $30. Digital monitors start at $30, but some fully automatic models can cost more than $100.
For many people, digital monitors are worth the extra expense. They are easier to use and leave less room for human error. And because the user doesn't have to listen for sounds through a stethoscope, they are an especially good choice for anyone with hearing problems.
What can I do to ensure accurate results?
As long as you're taking the trouble to measure your blood pressure, you should make sure the measurements will be as accurate as possible. First of all, find a cuff that actually fits your arm. When wrapped around your bare bicep, the cuff should fit snugly, but you should still be able to stick a finger under it. A doctor, nurse, or pharmacist can help you choose the kind that's best for you.
After you buy your home monitor, take it to your next doctor's appointment so you can check its accuracy against the office equipment. During this visit, your doctor or a nurse can answer any questions you may have about operating the device. Have your doctor recheck your monitor at least once each year.
The American Academy of Family Physicians offers these additional tips:
- Relax for a few minutes before checking your pressure.
- Don't talk while measuring your pressure.
- Sit still with your arm resting on a table or a desk. Your arm should be roughly level with your heart.
- When you put your monitor away, be careful not to twist the tubing.
- Keep the tubing away from heat, and check it regularly for cracks and leaks.
Checking your own blood pressure may not be the most interesting part of your day, but it could easily be the most lifesaving.
American Academy of Family Physicians information on high blood pressure http://www.familydoctor.org/healthfacts/092/
American Heart Association. Blood Pressure Guidelines
Journal of the American Medical Association, Dec. 10, 2013
American Academy of Family Physicians. Information from your family doctor. Blood pressure monitoring at home.
Classification of Blood Pressure for Adults, Merck Manual online
American Academy of Family Physicians. Blood Pressure Monitoring At Home.http://familydoctor.org/online/famdocen/home/common/heartdisease/treatment/128.html
American Heart Association. What is High Blood Pressure?
National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. Pediatrics. Vol. 114 No. 2, pp. 555-576.