How to measure your blood pressure at home, step by step

1. Use the right monitor

• An upper-arm cuff monitor. The American Heart Association recommends an automatic monitor with a cuff that goes around your upper arm. It does not recommend wrist or finger monitors.
• A validated model. Not every monitor on sale has been tested for accuracy. The AMA keeps a free list of validated devices at validatebp.org, or you can ask your pharmacist.
• The right cuff size. Measure around the middle of your upper arm and pick the cuff that matches. A cuff that is too small or too big gives a wrong reading.
• Check it against the office. Take your monitor to an appointment once a year so your doctor or nurse can compare it with theirs.

2. The 30 minutes before

For 30 minutes before you measure, avoid caffeine, smoking and exercise. The CDC also suggests not eating or drinking in that time. Go to the toilet first: a full bladder can raise the reading.

3. Sit the right way

1. Sit in a chair with your back supported and both feet flat on the floor. Do not cross your legs.
2. Rest your arm on a table so the cuff is at the level of your heart. A cushion under the arm helps.
3. Put the cuff on bare skin, not over a sleeve. The bottom edge sits just above the bend of your elbow.
4. Rest quietly for 5 minutes before you press start. No phone, no TV, no talking.
5. Stay still and silent while the cuff inflates and deflates.

4. Take two readings, a minute apart

Each time you measure, take a second reading about one minute after the first. The AHA, the AMA and the CDC all suggest at least two. Write both down: your doctor will use the average, not the lowest or the highest.

If the first reading is much higher than usual, do not panic. A single high number is common, especially if you were rushing. Rest, measure again and write down both.

5. Write it down straight away

Write the reading in your log before you put the monitor away. I have kept a paper log every day for twenty years, for a different condition, and the one rule that made it stick is this: write it down at the moment you measure, not later. A log that lives next to the monitor gets filled in. A log in a drawer does not.

Write the top number (systolic) and the bottom number (diastolic), your pulse if your monitor shows it, the time, and a word or two about anything unusual: coffee, a bad night, pain, a missed dose.

6. Measure at the same times each day

Blood pressure changes through the day, so readings are only comparable if they are taken at similar times. Most people measure in the morning and in the evening. Ask your doctor how often you should measure; when checking a new diagnosis or a medicine change, doctors often ask for a full week. See the best time of day to check your blood pressure.

Common mistakes

• Measuring right after coffee, a cigarette or climbing the stairs.
• Talking or looking at your phone during the reading.
• The cuff over a sleeve, or the arm hanging down at your side.
• Only writing down the "good" readings. Write every reading, including the high ones.
• Changing your medicine because of a few home readings. Talk to your doctor first.

Not medical advice. This guide is general information. Your target, how often to measure and your treatment come from your doctor, who knows your situation.

Questions

Sources

1. American Heart Association. Monitoring Your Blood Pressure at Home
2. CDC. Measuring Your Blood Pressure
3. American Medical Association. 7-step SMBP quick guide (self-measured blood pressure)
4. American Medical Association. Validated Device Listing (VDL) for blood pressure monitors
5. American Heart Association. Understanding Blood Pressure Readings

More guides

• How to keep a blood pressure logWhat to write down, and how to make the habit stick.
• Best time of day to check blood pressureMorning, evening, and why consistency matters most.
• How to average your blood pressure readingsThe sum your doctor actually looks at, with an example.
• Why home readings differ from the doctor'sWhite coat and masked hypertension, explained simply.
• Blood pressure and diabetesWhy both matter, the usual target, and how to track both.