High blood pressure: Get the most out of home monitoring

Checking your blood pressure at home is an important part of managing high blood pressure (hypertension). Home monitoring can help you keep closer tabs on your blood pressure while you are in a comfortable, familiar setting. Home monitoring can also help make certain your medication is working and help alert you and your doctors to potential health complications.

Because blood pressure monitors are available widely and without a prescription, home monitoring is an easy step you can take for yourself to improve your condition. Before you get started, it's important to know the right technique and to find a good system.

Why do I need to monitor my blood pressure at home?

Monitoring your blood pressure at home offers several benefits. It can:

• Help track your treatment. Self-monitoring provides vital information between visits to your doctor. The only way to know whether your lifestyle changes or your medications are working is to check your blood pressure regularly. Keeping track of changes can help you and your health care team make decisions about your ongoing treatment strategy, such as adjusting dosages or changing medications.
• Encourage better control. Taking your own blood pressure measurements has been shown to result in better blood pressure control and greater success meeting blood pressure targets. You gain a stronger sense of responsibility for your health, and you may be even more motivated to control your blood pressure with an improved diet, physical activity and proper medication use.
• Cut your health care costs. Home monitoring may cut down on the number of visits you need to make to your doctor or clinic. This can reduce your overall health care costs, lower your travel expenses and save in lost wages.

In addition, home monitoring can sometimes help when diagnosing high blood pressure is difficult. Your doctor may suspect, for instance, that your blood pressure goes up due to the anxiety associated with being at the doctor's office, but is otherwise normal — a condition called white-coat hypertension. Monitoring blood pressure at home, where anxiety won't cause those spikes, can help determine if you have true high blood pressure or simply white-coat hypertension. Monitoring your blood pressure at work, if privacy is possible, can help exclude white-coat hypertension as well.

Home and workplace monitoring may also help when the opposite occurs — your blood pressure seems fine at the doctor's office, but is elevated elsewhere. This kind of high blood pressure, sometimes called masked hypertension, is more common in women and those with cardiovascular risk factors, such as obesity, high blood cholesterol and high blood sugar.

Not everyone can track blood pressure at home. If you have an irregular heartbeat, for instance, home monitors might not provide accurate readings. In some cases, your physical condition may dictate what type of monitor you can use, or whether you can even use one at home. If you're overweight or very muscular, you'll need to find a monitor with an arm cuff that's large enough. If you have hearing loss, a monitor with a digital display may be more suitable.

Talk to your doctor, nurse or other health care professional about whether home monitoring is a good option. Keep in mind that a family member or friend who is properly trained may be able to take blood pressure measurements for you.

Types of home monitors

Today, most pharmacies and medical-supply stores or Internet sites have home blood pressure monitors. All monitors have the same basic components — an inflatable cuff or strap, a gauge for readouts and sometimes a stethoscope, depending on the model.

Cuff. The cuff consists of an inner layer made of rubber that fills with air and squeezes your arm. The cuff's outer layer is generally made of nylon and has a fastener to hold the cuff in place.

Gauge. Blood pressure monitors are either digital or aneroid. The aneroid monitors have a gauge with a dial on it that points at a number related to your blood pressure.

Stethoscope. Some blood pressure monitors come with a stethoscope. It's used to listen to the sounds your blood makes as it flows through the brachial artery in the crook of your elbow. However, without proper training, it's difficult to interpret those sounds. Digital blood pressure cuffs usually have a built-in sensor that records the information for you.

There are a couple of basic types of home blood pressure monitors:

• Manual devices. Manual blood pressure monitors consist of a stethoscope and an inflatable arm cuff connected by a rubber tube to a gauge that records the pressure. To use these monitors, you manually inflate the cuff that goes around your arm by pumping a bulb at one end of the tube. You also manually check your blood pressure with a stethoscope — listening for certain benchmark arterial blood sounds — and count your own heart rate. Manual monitors are usually less expensive than digital monitors.
• Digital devices. Digital monitors consist of a cuff and a gauge that records the pressure. The cuff automatically inflates at the touch of a button. These devices automatically calculate heart rate and measure your blood pressure by assessing arterial blood flow. Some even give you an error message if you aren't wearing the cuff properly. Digital monitors also deflate automatically. Digital monitors can be fitted on the upper arm, wrist or finger. Arm devices are the most accurate. Avoid devices that measure blood pressure in your finger, because they're not accurate. Wrist blood pressure devices are slightly more accurate than finger devices, but are still not usually recommended.

Each type has pros and cons. Talk over the choices with your doctor or nurse so that you pick the one that's best for your situation.

Public blood pressure machines

Don't rely on the free blood pressure machines commonly found in malls, pharmacies and grocery stores. They aren't accurate, and many aren't routinely checked and calibrated.

Features to consider

Features on home blood pressure monitors can vary widely, from bare-bones manual models to top-of-the-line fully automated devices that allow you to send data to your doctor's office through the phone lines. Here are some general features to consider when choosing a blood pressure monitor:

• Cuff size. Having a properly fitting cuff is the most important factor to consider when purchasing a home blood pressure monitor. Many monitors are available with different-sized cuffs to fit different-sized arms. Poorly fitting cuffs will not give accurate blood pressure measurements. Ask your doctor or nurse what cuff size you need. Larger cuffs may cost a bit more, but purchasing a monitor with a cuff that's too small won't be helpful.
• Display. The display that shows the blood pressure reading comes in various sizes. Be sure to get one with numbers you can easily read.
• Stethoscope. If you get a monitor with a stethoscope, you must be able to clearly hear the sounds through it. You also must know how to interpret those sounds — something your doctor or nurse can teach you.
• Validation. Check with your doctor or the manufacturer to be sure the monitor has been validated. Only validated instruments can be relied on for accurate readings.
• Cost. Your health insurance may not cover the cost of a home blood pressure monitor. Prices can vary from as little as $25 for manual monitors to well over $100 for automatic devices that come enhanced with memory and electronic printout ability.

Tips for accurate use

No matter what type of home blood pressure monitor you choose, proper use requires some practice and training. Take the device to your doctor or nurse or find a class at your local medical facility to make sure the one you've chosen is the best fit for you and to learn how to use the monitor accurately and keep it calibrated.

You can also follow these tips to help ensure accuracy when you measure your blood pressure at home:

• Before using a monitor for the first time, have your doctor or nurse check its accuracy against the office model. Also have your doctor or nurse watch how you use the device so that he or she can see if you're doing it properly.
• Take your blood pressure at consistent times, such as in the morning and in the evening.
• Use the same arm whenever you take your blood pressure. Note that many digital monitors are meant for use only on the left arm.
• Don't measure your blood pressure immediately after you wake in the morning. Wait an hour or so. If you exercise after waking, take your blood pressure before exercising.
• Avoid food, caffeine, tobacco and alcohol for 30 minutes before taking a measurement.
• Go to the toilet first. A full bladder can increase blood pressure slightly.
• Sit quietly for three to five minutes before taking a measurement.
• Sit in a comfortable position with your legs and ankles uncrossed and your back supported against a chair.
• Rest your arm, raised to the level of your heart, on a table, desk or chair arm. You may need to place a pillow or cushion under your arm to elevate it high enough.
• Don't talk while taking your blood pressure.
• Place the cuff on bare skin, not over clothing. Rolling up a sleeve until it tightens around your arm can result in an inaccurate reading, so you may need to slip your arm out of the sleeve.
• Take a repeat reading two to three minutes after the first one to check accuracy.
• If your monitor doesn't automatically log blood pressure readings or heart rates, write them down in your own log.
• Take the monitor to your medical office annually to be calibrated. If you drop the device or damage it, take it in to be checked before using it again, as it may no longer work properly.

Your blood pressure at home is usually slightly lower than it is in a medical office, typically by a measurement of about five points. For instance, a reading at home of 135/85 millimeters of mercury (mm Hg) is about the same as 140/90 mm Hg at the doctor's office.

Talk to your doctor about what your home blood pressure goal is. If you have diabetes, chronic kidney disease or cardiovascular disease, you may need a goal lower than that of someone without these conditions.

Blood pressure varies throughout the day, and readings are often a little higher in the morning. But contact your doctor if you have any usual or persistent increases in your blood pressure. Also ask what reading should prompt an immediate call to the medical office. In addition, if your home reading shows that your blood pressure is higher than normal and you experience symptoms such as severe headache, chest pain, numbness or tingling in the face or limbs, contact your medical office immediately or seek emergency treatment.

Long-term payoffs

If your blood pressure is well controlled, you may need to check it at home only a few days each month. If you're just starting home monitoring, if you're making any changes in your medications or other treatments, or if you have another health problem, such as diabetes, you may need to check it more often.

Home blood pressure monitoring is not a substitute for visits to your doctor. Even if you get normal readings, don't stop or change your medications or alter your diet without talking to your doctor first.

Monitoring your blood pressure at home doesn't have to be complicated or inconvenient. You might even find that you enjoy tracking your readings and that home monitoring gives you more control over your condition. And in the long run, you may risk fewer complications related to high blood pressure and enjoy a healthier life.

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