If you're one of the 73.6 million Americans with high blood pressure (hypertension), you should know that regular blood pressure monitoring is vital to manage this chronic condition successfully — which means getting regular blood-pressure readings at your doctor's office and checking your blood pressure at home.
“In my opinion, every single person who has high blood pressure should be monitoring it regularly at home,” says Suhail Ahmad, M.D., Medical Director of the Hypertension Clinic, at the University of Washington in Seattle. “In fact, I'll go farther and say that even people who have prehypertension [see sidebar] should monitor their blood pressure, too.”
JUST DO IT
Monitoring your blood pressure is quick, painless and gives your doctor important information. “Home monitoring helps us to be more accurate in diagnosing high blood pressure,” says Randal Thomas, M.D., Director of the Cardiovascular Health Clinic at Mayo Clinic in Rochester, MN. “It also helps us to be more accurate in assessing how well high blood pressure is being controlled” with lifestyle changes and medication.”
“We need blood pressure data because patients can't feel what their blood pressure level is. The only way to know is to take a blood pressure reading,” says Aram Chobanian, M.D., Dean Emeritus of the Boston University School of Medicine. “Doing this regularly at home is helpful because a patient's average blood pressure reading is much more important in assessing overall cardiovascular disease risk than a single reading here and there.”
A 2007 study published in the journal Hypertension suggests that patients who monitor their blood pressure at home may also need less medication to keep the condition in check. In part, this may be because patients who keep tabs on their blood pressure at home are more motivated to stick to their doctor's recommendations about diet, exercise and taking their medications.
Also, some people have “white coat hypertension” — blood pressure readings tend to be higher in the doctor's office than at home. “When I see a patient with repeated readings of high blood pressure in the office, I must rule in or rule out white coat hypertension,” says Chobanian. “The way to do that is to have the patient record blood pressure levels at home over time so I can base my diagnosis and treatment on accurate information.”
GET THE GEAR
High-quality home blood pressure monitors are widely available online, as well as at pharmacies and medical supply stores for about $60–$100.
The American Heart Association recommends an automatic cuff-style model — you put the cuff on your upper arm and press a button, instead of inflating the cuff with a hand-held pump. “Those are a better bet than the finger and wrist versions, which are less accurate, or taking it manually, which requires you to learn to identify heart sounds,” says Thomas.
Ahmad, for one, prefers styles with a soft arm cuff. “Many people are buying machines with a rigid cuff, but I think the soft cuff provides more accurate information,” he says.
Make sure the display is easy to read and, if your budget permits, choose a model that can store your measurements. Also, look for the “Works with HealthVault” logo, so you can hook your monitor to your computer and upload your readings to www.Heart360.org, the AHA's free online Cardiovascular Wellness Center.
At Heart360™ you can log your blood pressure, cholesterol and glucose readings; track type and amount of physical activity; record weight gain or loss; and keep a record of current and past medications and their doses. Your entries are stored in a secure, password-protected system, and you can even create reports with all the data you've input and print them out or e-mail them to your doctor before your appointment.
THE RIGHT TOUCH
Today's home blood pressure monitors are easy to use, but correct technique is still important. Your first step is to have your doctor check the monitor to ensure it is working properly, and take it back for another look once a year — sooner, if you've dropped it.
“We calibrate the patient's monitor with our equipment to make sure it's accurate,” says Craig B. Langman, M.D., head of Kidney Diseases at Children's Memorial Hospital in Chicago. “If the home-monitoring device is inaccurate, it may harm the patient by giving faulty data for the physician to use as a basis for determining and adjusting therapy.”
Your doctor will also check that the cuff on the monitor is the right size for you — you can get an artificially high reading by using a cuff that's too small, warns Langman — and will put you through your paces to make sure your technique produces accurate readings.
As a rule, you can't go wrong if you follow these simple steps:
▪ Avoid exercise, caffeine, nicotine and alcohol for 30 minutes before measuring your blood pressure;
▪ Use the bathroom first, as a full bladder can raise blood pressure slightly;
▪ Sit in a comfortable chair that offers firm back support;
▪ Keep your feet flat on the floor and don't cross your legs or ankles;
▪ Use the same arm each time and wrap the cuff around your bare arm. When you wear long sleeves, slip the arm out from the sleeve rather than pushing it up over the cuff, which could distort the reading;
▪ Rest your arm on a flat surface so your upper arm is at heart level;
▪ Don't talk while you take your blood pressure;
▪ Take two or three readings at least one minute apart;
▪ Write down your results if your machine doesn't record them, including the date and time;
▪ Understand normal daily variations in blood pressure — it may be higher in the morning — and whether your physician wants you to always take your blood pressure at the same time or prefers to see readings from different times of day; and
▪ Know when you need to report unusual results to your doctor.
The Mayo Clinic's Thomas believes that patients who monitor their blood pressure at home are active partners with their doctors. “They're getting immediate feedback as to what their therapy is doing, which reinforces what their clinician has recommended,” he says. “That, in turn, leads to better results. It's a very positive cycle.”
HOW HIGH IS TOO HIGH?
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In 2003, a coalition of 46 organizations led by the American Heart Association, issued revised blood pressure guidelines that redefined 120/80 mm Hg — formerly considered “normal” blood pressure as “prehypertension” — an early warning that high blood pressure could develop, and a signal to cut down on sodium intake and incorporate more physical activity into your daily routine.
The new normal for all adults 18 and over is systolic pressure (the upper number in the blood pressure reading, when your heart pumps) below 120 and diastolic pressure (the lower number) below 80, when your heart relaxes between beats).
“Risk and incidence of high blood pressure doesn't start at age 18, but diagnosing the condition in infants, kids and adolescents is tricky,” says kidney disease specialist Craig B. Langman, M.D., of Children's Memorial Hospital in Chicago. Until late adolescence, a child's blood pressure tends to be lower than an adult's and doctors will take your child's age, height and gender into account. Your child has hypertension when blood pressure is in the 95th percentile compared to his or her peers.
“But the effects of high blood pressure are the same regardless of the patient's age — prolonged hypertension will lead to long-term alteration in the function of the kidneys and heart, and may also lead to stroke, even in young people,” says Langman. “Once high blood pressure has been diagnosed, it's never too soon – even in children – to monitor and treat it.”
If you haven't been diagnosed and want to understand more about your risk of developing high blood pressure, visit www.heart.org/hbprisk to fill out an online risk assessment and get a detailed report of where you stand and how you can maintain a healthy blood pressure level.
© 2009 American Heart Association, Inc.