Understanding Upper Arm and Wrist Monitors

Home blood pressure monitors come in two main styles: those with a cuff for the upper arm and those worn on the wrist. Both use the same automatic measuring method, but they are not equally forgiving. Knowing the differences helps you pick the right type and use it properly.

How both types work

Automatic monitors use the oscillometric method. The cuff inflates until it briefly stops blood flow, then deflates slowly. A sensor detects the vibrations of the artery wall as blood begins to flow again, and the device calculates systolic and diastolic pressure and pulse from the pattern.

Upper arm monitors

The cuff wraps around the upper arm, over the brachial artery, and connects by a tube to a separate unit with the display.

Advantages

• The upper arm sits naturally near heart level when you are seated at a table.
• The brachial artery is larger and is the site used in clinics and in most research.
• More models have been independently validated.
• Different cuff sizes are available.

Drawbacks

• Bulkier to store and carry.
• The cuff can be awkward to put on alone at first.
• People with very large arms, or arms shaped so that a cuff does not sit well, may struggle to find a fit.

An example is our Automatic Upper Arm Blood Pressure Monitor, which includes a cuff for arms of 22 to 32 cm.

Wrist monitors

The cuff and display form a single unit that fastens around the wrist.

Advantages

• Small, light and easy to travel with.
• Quick to put on, with no sleeve to roll up.
• Useful for people who cannot use an upper arm cuff because of arm size, pain, limited mobility or a medical reason such as surgery or lymphedema on that side.

Drawbacks

• The arteries at the wrist are narrower and closer to the skin, which makes readings more variable.
• Results change with the height of the wrist relative to the heart. A wrist held too low reads high; too high reads low.
• Bending or tensing the wrist affects the result.

Our Automatic Wrist Blood Pressure Monitor is a compact option with a storage case.

What health organizations advise

Guidance for home monitoring generally favors an automatic monitor with an upper arm cuff. The British Heart Foundation, for example, advises ideally choosing a monitor that measures at the upper arm, and adds that people who cannot use an upper arm cuff can use one that wraps around the wrist instead.

So a wrist monitor has its place. For someone who cannot use an arm cuff, a validated wrist device used with careful technique may be the practical choice. Discuss it with your doctor, and have the device checked against a clinic measurement.

Using a wrist monitor correctly

1. Sit with your back supported and feet flat, and rest for five minutes.
2. Fasten the monitor on your bare wrist as the instructions show, usually with the display on the inner side.
3. Rest your elbow on a table and raise your wrist to heart level. Many people support it on a cushion or hold the arm across the chest.
4. Keep the wrist straight and the hand relaxed.
5. Stay still and silent during the measurement.
6. Take two readings a minute or two apart.

Comparing the two at a glance

• Recommended for routine home use: upper arm.
• Sensitivity to position: moderate for upper arm; high for wrist.
• Portability: wrist is better.
• Cuff sizing: upper arm requires the right cuff; wrist monitors fit a stated range of wrist sizes.
• Validated models available: many for upper arm; fewer for wrist.

Validation applies to both

Whichever type you choose, check that the specific model has been validated for accuracy. In the United States, the Validated Device Listing maintained by the American Medical Association identifies devices that meet its criteria.

Which should you choose?

• Choose an upper arm monitor if you can use one comfortably and a cuff fits your arm.
• Consider a wrist monitor if an upper arm cuff is not possible or you need a travel device, and you are confident you can position it correctly every time.
• If you own both, do not mix their readings in the same record without noting which device was used.

The bottom line

Upper arm monitors are the default recommendation because they are less affected by position. Wrist monitors trade some reliability for convenience and need strict technique. Compare both types in our heart and blood pressure department.

Sources

1. British Heart Foundation. How to measure your blood pressure at home.
2. Centers for Disease Control and Prevention. Measuring Your Blood Pressure.
3. American Medical Association. US Blood Pressure Validated Device Listing.
4. NHS. Blood pressure test.