By Partners Harvard Medical International
The American Heart Association recently recommended blood pressure checks be done at home. Read on to find out why – and how to do them right.
The American Heart Association recently recommended blood pressure checks be done at home. Read on to find out why - and how to do them right.
Your blood pressure changes from hour to hour, sometimes even minute to minute. Standing up from a chair, watching an exciting show on TV, eating a meal, listening to music, being stressed and even the time of day all influence your blood pressure. It jumps around so much that you're more likely to get a "normal" reading if you check it at home rather than in the doctor's office.
That idea underlies a new recommendation from the American Heart Association (AHA), American Society of Hypertension, and Preventive Cardiovascular Nurses Association. They urge individuals with high blood pressure, or at high risk for developing it, to become blood pressure do-it-yourselfers. There are many good reasons to follow their advice.
The benefits of DIY readings
• Find your real blood pressure The measurement your doctor or nurse takes is just a single frame from an ongoing movie. In some individuals, that snapshot tells the whole story, and is an excellent approximation of their usual blood pressure. In others, it isn't.
Up to 20% of people diagnosed with high blood pressure have "white-coat hypertension". This is a temporary spike in blood pressure brought on by the stress of trekking to and seeing a doctor. Still others have what's called "masked hypertension" - normal blood pressure in the doctor's office but high blood pressure everywhere else.
• Improve your control People who check their blood pressure at home tend to be more successful at keeping it under control. Timely feedback helps. Instead of a getting a blood-pressure reading once every few months under unusual conditions - in a doctor's office - you can get a reading every week or so at home.
Taking the measurements yourself also helps. People who actively participate in their care generally do better than those who take a hands-off, let-the-doctor-do-it approach.
• Track your progress You can't feel your blood pressure get better - or worse. Measuring it at home offers vital information about whether your lifestyle changes and the medication you're taking are having their desired effects.
• Save time and medication Monitoring your blood pressure at home may mean fewer trips to the doctor's office. If you have "white-coat hypertension", it may also mean taking fewer, or no, blood pressure medicines.
• Run with the healthy crowd Of every 100 people with high blood pressure, 70 or more don't have it under control. Checking your pressure at home and acting on the results can help you join the healthy crowd who do. A study shows that people who checked their blood pressure at home and emailed the results to a pharmacist who offered advice were far more likely to keep their blood pressure in check than those who merely measured it at home or those who had it taken by a doctor every now and then (Journal of the American Medical Association, June 25, 2008).
If you have high blood pressure, it's a good idea to check your blood pressure at home.
Use an automatic monitor with a cuff that fits around your arm and that keeps track of your readings.
Check your blood pressure once in the morning and once in the evening for a week, then 1 or 2 days a month after that.
Who needs to do this?
The new recommendation says home monitoring should be done by most people "with known or suspected hypertension". That includes the whopping 73 million Americans with high blood pressure. It also includes the millions more with type 2 diabetes or chronic kidney disease, who are at high risk for developing high blood pressure.Women who become pregnant should also consider checking their blood pressure at home, since high blood pressure is a common, and problematic, side effect of pregnancy. You might also think about it if you're seriously overweight, if you smoke, or if high blood pressure runs in your family.
Picking the right machine
There are dozens of different home blood pressure monitors on the market. For best accuracy and ease of use, buy one with a cuff for the upper arm that automatically inflates and automatically records the pressure.
Models that store readings for a week or 2 can simplify record-keeping.
Buy one that meets pre-set standards. The AHA doesn't recommend wrist or finger home blood pressure monitors.
The September 2008 issue of Consumer Reports compares home blood pressure and blood sugar monitors. The ReliOn HEM-74CREL ($50) got a "best buy" rating, while the Omron Elite 7300W ($75 to $100) was the top-rated machine.
Do it right
When it comes to measuring blood pressure, technique matters. Doing it wrong can give you a reading that's too high or too low. At www.health.harvard.edu/128 you can see a brief video on how to use a home blood pressure monitor effectively.
There are 2 things to do before you start. First, check your monitor against the one in your doctor's office. Second, make sure you have the right size cuff - the inflatable part of the monitor should encircle at least 80% of your upper arm.
When you first start to check your blood pressure at home, measure it early in the morning, before you've taken your blood pressure pills, and again in the evening, every day for a week. After that, follow the plan your doctor recommends, or check it 1 or 2 days a month.
When taking a reading:
• Avoid caffeinated or alcoholic beverages, and don't smoke, during the 30 minutes before the test.
• Sit quietly for 5 minutes with your back supported and feet on the floor.
• Elbows up When making the measurement, support your arm so your elbow is at the level of your heart.
• Push your sleeves out of the way and wrap the cuff over bare skin. Measure your blood pressure according to the machine's instructions. Leave the deflated cuff in place, wait a minute, then take a second reading. If the readings are close, average them. If not, repeat again and average the 3 readings.
• Don't panic if a reading is high Relax for a few minutes and try again.
• Keep a record of your blood pressure readings and the time of day they are made.
Checking blood pressure at home won't cure your hypertension, but it will help control the most common cause of stroke and a big contributor to heart attack, heart failure, and premature death.
Source: Harvard Health Publications. Copyright 2008 President and Fellows of Harvard College. All rights reserved.