Get the most out of home blood pressure monitoring

By Mayo Clinic Staff

Checking blood pressure at home is an important part of managing high blood pressure, called hypertension.

The American Heart Association (AHA) and other organizations recommend that people with high blood pressure monitor their blood pressure at home. The medical term for this is self-measured blood pressure (SMBP). Regularly checking blood pressure at home helps your healthcare team learn if treatment is working.

Home blood pressure monitors are available widely and without a prescription. But it's important to know how to find a good home blood pressure monitor and to use it correctly.

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

Self-measured blood pressure can:

• Help with early diagnosis. Checking your blood pressure at home can help your healthcare professional diagnose high blood pressure earlier than if you only get blood pressure checks in a medical office. Home monitoring is especially important for people with elevated blood pressure or another condition that also could cause high blood pressure, such as diabetes or kidney disease.
• Help learn if treatment is working. Keeping track of your blood pressure at home is a helpful way to know whether your lifestyle changes or blood pressure medicines are working. Your blood pressure readings can help you and your care team make decisions about treatment, such as changing the dose or the medicine.
• Encourage better health. Self-monitoring might help you feel more motivated to control your blood pressure with improved diet, physical activity and proper medicine use.
• Cut your health care costs. Checking your blood pressure at home might help reduce the number of medical visits you need.
• Tell if you have higher blood pressure during health checkups. Some people have spikes in blood pressure due to nervousness during a medical visit. This is called white coat hypertension. Other people whose blood pressure is OK at a medical office may have higher blood pressure elsewhere, called masked hypertension. Keeping track of blood pressure at home can help determine if you have true high blood pressure.

Not everyone can track blood pressure at home. For those with irregular heartbeats, home blood pressure monitors might not give the correct reading.

Types of home monitors

Most pharmacies, medical supply stores and some websites sell home blood pressure monitors. Experts recommend an automatic or electronic device. Your healthcare professional can help you pick the monitor that's best for you.

Blood pressure monitors generally have the same basic parts:

• Inflatable cuff. The cuff's inner layer fills with air and squeezes the arm. The cuff's outer layer has a fastener to hold the cuff in place. As the cuff lets out air, the device measures how fast the heart is beating and how well blood is moving through the arm artery.
• Gauge for readouts. Some blood pressure monitors can take several readings and report the averages.

Digital monitors that are fitted on the upper arm are often the most accurate.

Some people with very large arms may not have access to a well-fitting upper arm cuff at home. If so, measuring blood pressure at the wrist or lower arm may be OK if used as directed and checked against measurements taken in your healthcare professional's office. For the most reliable blood pressure measurement, the American Heart Association recommends using a monitor with a cuff that goes around your upper arm, when available.

For people who can't check blood pressure at home, many pharmacies and stores have public blood pressure devices. The accuracy of these devices may vary.

Features to consider

When choosing a blood pressure monitor, consider:

• Cuff size. Having a properly fitting cuff is important. Cuffs that fit poorly won't give accurate blood pressure measurements. Ask your healthcare professional what cuff size you need.
• Display. The display that shows blood pressure measurements should be clear and easy to read.
• Cost. Prices vary. Ask your health insurance provider if your policy covers the cost of a home blood pressure monitor.

Device accuracy

Once a year, check the accuracy of your monitor by bringing it to your healthcare professional's office. Your healthcare team can compare your monitor's readings with those taken at the office.

Tips for accurate use

No matter what type of home blood pressure monitor you choose, proper use needs training and practice. Take the device to your healthcare professional to make sure the one you've chosen is the best fit for you. Learn to use the monitor correctly.

To help make sure you're checking your blood pressure at home correctly:

• Check to be sure your device is correct. Before using a home blood pressure device, have your healthcare team compare the readings from your device with the readings from the device in the medical office. Also have them watch you use the device to see if you're doing it correctly. If you drop the device or damage it, have it checked before using it again.
• At the beginning, measure your blood pressure at least twice daily. Take it first in the morning before eating or taking any medicine. Take it again in the evening. Each time you check your blood pressure, take two or three readings to make sure your results are the same. Your healthcare professional might suggest taking your blood pressure at the same times each day.
• Check your blood pressure before breakfast. But don't take it right when you wake up. Get dressed and ready for your day first. Then check your blood pressure before eating or taking your medicines. If you exercise after waking, take your blood pressure before exercising.
• Do not use caffeine, tobacco and alcohol for 30 minutes before taking a reading. Also, empty your bladder first. A full bladder can make blood pressure go up a little bit.
• Sit quietly before and during monitoring. When you're ready to take your blood pressure, sit for five minutes in a comfortable position with your legs and ankles uncrossed. Your back should be supported against a chair. Try to be calm and not think about stressful things. Don't talk while taking your blood pressure.
• Make sure your arm is positioned correctly. Always use the same arm when taking your blood pressure. Rest your arm, raised to the level of your heart, on a table, desk or chair arm. You might need to place a pillow or cushion under your arm to raise it high enough.
• Place the cuff on bare skin, not over clothing. A rolled-up sleeve that's tight around your arm can affect the reading. You may need to slip your arm out of the sleeve.
• Take a repeat reading. Wait 1 to 3 minutes after the first reading, and then take another. If your monitor doesn't keep track of blood pressure readings or heart rates, write them down.

Blood pressure varies throughout the day. Readings are often a little higher in the morning. Also, your blood pressure might be slightly lower at home than in a medical office.

Contact your healthcare team if you have any unusual increases in your blood pressure or if your blood pressure stays higher than usual. Ask them at what reading you should call the medical office right away.

Tracking your blood pressure readings

Some people use a notebook to record their blood pressure readings.

If you have an electronic personal health record, you might choose to record your information using a computer or mobile device. This gives you the choice of sharing your readings with your healthcare team and family members. Some blood pressure monitors upload this data automatically.

Long-term benefits

If your blood pressure is well controlled, ask your healthcare professional how often you need to check it. You might be able to check it only once a day or less often. If you're just starting home monitoring or changing treatment, they might recommend checking blood pressure starting two weeks after treatment changes and a week before your next appointment.

Home blood pressure monitoring is not a substitute for medical visits. Home blood pressure monitors might not always be correct. Even if you get readings that are typical for you, don't stop or change your medicine or your diet without talking to your care team first. However, if your at-home readings show that your blood pressure is well managed, you might be able to make fewer medical visits.