Wrist blood pressure monitors are a popular way to take blood pressure at home. Their small size and digital face make them convenient to use. Plus, many wrist monitors store past readings and can be used to track your blood pressure over several weeks.
However, they’re not the most accurate way to measure your blood pressure. Blood pressure readings tend to skew higher when measured with wrist monitors.
In fact, the American Heart Association (AHA) advises against wrist blood measures for home monitoring. According to the AHA, home monitors that are used on the upper arm are generally more accurate.
Why are wrist blood pressure monitors less accurate?
There are two reasons that wrist blood pressure monitors are less accurate than upper arm monitors. The first reason is the anatomy of your wrist itself. The blood vessels in your wrist are more narrow and sit closer to your skin than the blood vessels in your upper arm. This makes it harder to get an accurate reading on your wrist.
The other major reason is user error. While wrist monitors might seem like the easiest home monitors to use, it’s actually difficult to position them correctly. Many people assume that you can just place a wrist monitor on your wrist and hit a button, but that’s not the case.
How to get the most accurate reading on a wrist monitor
In order to get an accurate reading with a wrist blood pressure monitor, you need to:
- Take the reading with your arm and wrist at heart level.
- Place the blood pressure monitor at the exact right spot on your wrist.
This means that a reading from a wrist monitor is likely to be inaccurate. While being a little off might not be a big deal if you want to casually check your blood pressure occasionally, that’s not the case for most people who are monitoring their blood pressure at home.
Often, if you’re taking your blood pressure at home, you’re concerned about your blood pressure — or you might have even been asked by a doctor to do at-home tracking. This makes the accuracy of readings very important.
Ranking of home blood pressure monitors
Do your research before buying an at-home blood pressure monitor. Blood pressure monitors can be found at many price points and from many different companies.
You can pick one up from your local pharmacy or order one online. Before shopping, it can help to know what kind of monitor you need. You can see the accuracy of common home monitor types below.
Most accurate: digital arm monitors
Digital upper arm monitors are a great way to measure your blood pressure at home. They’re more accurate than wrist monitors and they’re easier to master than analog upper arm monitors.
Their accuracy and ease of use make them a smart choice for most people. Plus, many digital arm monitors have user-friendly features like automatic cuff inflation and blood pressure reading storage.
However, digital arm monitors aren’t perfect. They’re more expensive than other types of at-home monitors. In fact, some models are priced at over $100. They’re also not always completely accurate.
Moving your body while the monitor is on can give a false read. Some digital arm monitors can’t be used on your right arm, making those models difficult for some people to use. Finally, people with irregular heartbeats might not be able to get an accurate blood pressure reading from any type of digital monitor.
Runner up: analog arm monitors
Analog arm monitors are also called aneroid monitors. You use them to manually check your blood pressure. They have a rubber ball you squeeze to inflate the cuff around your arm. You then watch a dial and listen to an attached stethoscope to get a reading. They are often much less expensive than digital arm monitors.
Analog monitors can be accurate, but they’re hard for many people to use. Reading the dial can be much more difficult than reading a digital screen, and people with hearing loss might have trouble hearing their heartbeat in the stethoscope.
Plus, the dial and other parts of an analog arm monitor can become damaged easily. When the parts are damaged, the monitor will not be as accurate.
Least accurate: wrist monitors
Wrist monitors are compact and convenient, but they don’t always provide the most accurate readings. They’re generally best for travel or taking your blood pressure on the go. They can be a good way to get a quick idea of your blood pressure when you don’t need an exact reading.
Wrist monitors can be helpful for people whose arms don’t fit the sizing for at-home upper arm monitors. People who typically find blood pressure readings to be painful might also benefit from a wrist monitor.
Plus, they’re a good alternative for people who have trouble using an upper arm monitor due to a limited ability to move their arms and hands.
How to best check your blood pressure at home
No matter what type of monitor you use, you can take steps to make sure you’re getting the most accurate reading possible. For accurate readings, it’s a good idea to:
- Make sure you know how to work your at-home monitor. Read the instructions carefully and ask a healthcare professional to show you if you’re still unsure how to use it.
- Avoid cigarettes, caffeine, and exercise for at least 30 minutes before you take your blood pressure.
- Take your blood pressure at the same time every day.
- Use the bathroom and make sure your bladder is empty before you begin.
- Try to sit still for at least 5 minutes before taking your blood pressure.
- Roll up your sleeve so you’re not taking your reading over clothing.
- Sit with your back straight and feet flat on the floor. Don’t cross your legs.
- Rest your arm on a flat surface like a table or desk.
- Place the cuff correctly on your arm. Check the instructions again if you need a refresher.
- Take two or three readings and record them all.
Tips for analog blood pressure monitors
If you’re using a digital wrist or upper arm monitor, your results will be displayed on the screen. If you’re using an analog monitor, you’ll need to read the numbers yourself.
Analog blood pressure monitors have a dial with a hand, much like the hands of a clock, on it. You’ll read this hand to find your blood pressure. A healthcare professional can show you how to do this on your specific monitor model, but you can see the general steps below:
- Wrap the cuff around your arm and make sure you can see the dial.
- Place the flat base of the stethoscope under the cuff and put the ear tips in your ears.
- Turn the valve on the bulb to close the airflow.
- Squeeze the bulb rapidly to inflate the cuff.
- Keep squeezing until the hand on the dial hits 180.
- Slowly turn the valve back to deflate the cuff.
- Listen for your pulse in the stethoscope and record where the hand is on the dial when you first hear it.
- Keep listening until you can no longer hear your pulse, and record where the hand is on the dial when you stop hearing your pulse.
- Let the rest of the air out of the cuff.
As an example, if you first heard your pulse when the hand was at 135 on the dial and last heard it when the hand was at 78, that would be a blood pressure reading of 135/78.
If you have concerns
It’s important to remember that a single high blood pressure reading isn’t a reason to worry. If you’re taking your blood pressure at home and you get a few readings that don’t match what you normally get at the doctor’s office, it’s probably not cause for concern. However, if you’re consistently getting readings that seem wrong to you, it’s a good idea to double-check.
One way to check is at your local pharmacy. Some pharmacies have a blood pressure monitor on-site that you can use to get a reading. These blood pressure machines are often free or low-cost. Other pharmacies can take your blood pressure for you. This service might be free or covered by your insurance.
You can also check with your doctor at your next appointment. Bring your blood pressure monitor with you and have your doctor check it for accuracy. They might be able to help you find errors with your monitor. For example, they’ll be able to tell if your monitor is the wrong cuff size.
When to talk with a professional
Getting your blood pressure taken is a standard part of most medical appointments, but it’s not always the best way to get an understanding of your blood pressure. After all, your blood pressure is affected by the things you do throughout your day, and a single high or low reading might not reflect your normal blood pressure.
White coat hypertension
Additionally, some people always have higher than normal blood pressure results at a doctor’s office. This is known as white-coat hypertension and it’s common in people who find visiting the doctor stressful.
That’s why one of the most accurate ways to know if your blood pressure is a concern is at-home monitoring. When you monitor at home, you can get a better idea of what your blood pressure is like on average days. In some cases, your doctor might ask you to gather this data for them. You might monitor your blood pressure at home every day for a month or two and then consult with a doctor to go over the results.
Starting the conversation
At-home readings can also start the conversation with a medical professional. For example, if you’re consistently getting high blood pressure readings of higher than 130/80, it’s a good idea to bring them up at your next doctor visit.
When it’s a medical emergency
A blood pressure of 180/120 or higher can be a sign of a medical emergency.
If you get this reading, wait 5 minutes and take your blood pressure again. If your pressure is still 180/120 or above, you should seek immediate medical care.
If your blood pressure is over 180/120 and you have certain symptoms, do not wait 5 minutes. Those symptoms include:
- shortness of breath
- chest pain
- back pain
- difficulty speaking
- vision changes
An extremely high blood pressure along with any of these symptoms could lead to organ failure. It’s vital that you call 911 right away in this situation.
The bottom line
Wrist blood pressure monitors are fast and convenient, but they’re not always the most accurate. Wrist monitors are difficult to use correctly and need to be placed extremely carefully for accurate readings.
For most people, digital upper arm monitors are a better choice. They’re easy to use and provide accurate readings in most cases. Talk to a healthcare professional if you’re not sure what the best monitor is for you. They can help you select a monitor and can teach you how to use it.