How to Measure Your Blood Pressure at Home, Properly

A home blood pressure monitor is one of the most useful health devices you can own. Readings taken at home, over days, often show your usual blood pressure better than one reading at a clinic, where nerves can push it up. But home readings are only as good as the way you take them. Crossed legs, a cuff that’s too small, or an arm hanging at your side can each add several mm Hg.

This is the method from the American Heart Association’s scientific statement on measuring blood pressure, and its joint policy statement with the American Medical Association on home monitoring. It’s general information, not medical advice: your clinician may ask you to measure differently.

Choose a Validated Upper-Arm Monitor

• Upper arm, not wrist. The AHA recommends an automatic (oscillometric) monitor with a cuff for the upper arm. It has strong reservations about wrist monitors, except for people who can’t use an upper-arm cuff.
• Validated. Many monitors have never been tested against a standard protocol. Check a list: in the US, the AMA’s validatebp.org; in Canada, Hypertension Canada’s recommended devices.
• No cuffless devices for now. The 2025 AHA/ACC guideline advises against relying on cuffless devices, smartwatches included, until they’re shown to be more accurate.

Get the Cuff Size Right

A cuff that’s too small gives a reading that’s falsely high. The inflatable bladder inside the cuff should go around 75% to 100% of your arm. Measure around the middle of your upper arm and check the cuff’s printed range. If your arm is near the top of the range, a large cuff may be the right one. Put the cuff on bare skin, not over a sleeve.

Prepare for Five Minutes

• Empty your bladder first.
• Avoid caffeine, smoking, and exercise for 30 minutes before.
• Sit quietly for at least five minutes before the first reading.
• Don’t talk, read your phone, or watch TV during the rest or the reading.

Sit the Right Way

How you sit changes the number, sometimes a lot. The AHA statement reports:

• Back supported. Sitting without back support can raise systolic blood pressure by 5 to 15 mm Hg. Use a chair with a back.
• Feet flat, legs uncrossed. Crossed legs can raise systolic by 5 to 8 mm Hg and diastolic by 3 to 5 mm Hg.
• Arm supported at heart level. Rest your arm on a table so the cuff is level with your heart. An arm held up by its own muscles, or hanging below the heart, gives readings that are too high.

Lying down gives different numbers again: systolic has been reported 3 to 10 mm Hg higher lying down than seated. Seated is the standard. If you also measure standing, for example because you get dizzy on standing up, record which is which.

Which Arm?

The first time, measure both arms. If one is consistently higher, use that arm from then on, and tell your clinician about a persistent difference. Then always use the same arm.

How Many Readings, and When

The AHA/AMA statement describes the usual home schedule:

• Two readings, at least one minute apart, each time.
• Twice a day: in the morning before any blood pressure medicine, and in the evening before bed.
• For seven days if you can, and at least three.
• Average all the readings for the period, not just the best or the worst.

Single readings vary from minute to minute. The average over a week is the number to talk about with your clinician.

Write Down the Details

A reading means more when you know how it was taken: which arm, sitting or lying, morning or evening, and anything unusual, like a missed dose, a bad night, or a stressful call. That context is what turns a list of numbers into something your clinician can use.

Recording It in Kaizora

In Kaizora, a blood pressure reading is one entry on the Vitals page, with its Systolic Blood Pressure, Diastolic Blood Pressure, and the pulse the cuff took, at one time.

1. Log a reading. On Vitals, choose Log, then Blood Pressure. Enter the systolic, diastolic, and pulse, set the time and choose your monitor as the device. Write the arm and position in the notes, and anything unusual. See Logging a Value.
2. Or import it. Readings from a Withings monitor come in with your Withings data export, and readings saved to Apple Health come in with its export. See Importing From Withings and Importing From Apple Health. Imported readings are read-only but for their notes, where you can write the arm and position.
3. Follow a 7-day average. A habit on an averaged metric is checked by its average over the habit’s window, so a habit on Systolic Blood Pressure such as “at most 130 mm Hg on average over any 7 days”, with the target your clinician gives you, checks the average of your last 7 days’ readings every day. See Habits.
4. Add your ranges. If your clinician gives you thresholds, add them as reference ranges on Systolic and Diastolic Blood Pressure, so readings outside them are flagged on the chart and on Home. See Reference Ranges.
5. Mean arterial pressure is calculated from each reading’s systolic and diastolic, so you don’t log it.

Each value names its monitor. If you switch monitors, filter by device to compare them. See Why Your Devices Disagree.

The Short Version

• Use a validated upper-arm monitor with the right cuff size, on bare skin.
• Rest five minutes; sit back, feet flat, legs uncrossed, arm on a table at heart level; don’t talk.
• Take two readings a minute apart, morning and evening, for a week, and average them.
• Use the same arm each time, the higher one if they differ, and note how each reading was taken.

Want a place to keep your readings with their device and notes? Kaizora is free to start.

Sources

• Muntner P et al., “Measurement of blood pressure in humans: a scientific statement from the American Heart Association,” Hypertension 73, no. 5 (2019): e35–e66. doi:10.1161/HYP.0000000000000087
• Shimbo D et al., “Self-measured blood pressure monitoring at home: a joint policy statement from the American Heart Association and American Medical Association,” Circulation 142, no. 4 (2020): e42–e63. doi:10.1161/CIR.0000000000000803
• Jones DW et al., “2025 AHA/ACC/AANP/AAPA/ABC/ACCP/ACPM/AGS/AMA/ASPC/NMA/PCNA/SGIM guideline for the prevention, detection, evaluation and management of high blood pressure in adults,” Hypertension 82, no. 10 (2025): e212–e316. doi:10.1161/HYP.0000000000000249
• American Medical Association, US Blood Pressure Validated Device Listing; Hypertension Canada, Recommended Devices.