How to Keep a 7-Day Blood Pressure Diary at Home: UK Guide
A seven-day blood pressure diary is a practical way to record readings taken at home and share them with your GP or practice nurse. Rather than relying on one number, a series of carefully taken measurements can help a clinician understand your blood pressure over time. This UK guide explains how to set up a diary, when to measure, what to write down and which mistakes to avoid.
Important: This is general information for adults, not a diagnosis or an instruction to change medication. Follow the measurement schedule given by your own clinician, especially if you are pregnant, have an irregular heartbeat or another condition requiring individual advice.
What is a seven-day blood pressure diary?
It is a dated record of home blood pressure readings, usually taken in the morning and evening. Each entry contains the systolic reading (the upper number), the diastolic reading (the lower number), and ideally the pulse, time and any relevant notes. You can use a printed sheet, notebook or digital document. The British & Irish Hypertension Society provides a downloadable home blood pressure diary.
Why record blood pressure for several days?
Blood pressure changes naturally during the day and can be affected by activity, stress, posture and measurement technique. A diary makes it easier to see a pattern and gives your clinician more information than a single reading. Home monitoring may also help when clinic readings differ from readings at home. It is not a substitute for a professional assessment.
How often should you take readings?
For home blood pressure monitoring used to confirm a diagnosis, NICE guideline NG136 recommends:
- Take two consecutive readings each time, at least one minute apart, while seated.
- Record readings twice daily, ideally in the morning and evening.
- Continue for at least four days, ideally seven.
- For the clinical average used to confirm a diagnosis, discard day-one readings and average the remaining measurements.
These are NICE recommendations for a particular diagnostic purpose, not a universal instruction for everyone to measure twice daily indefinitely. Your GP may recommend a different schedule for ongoing monitoring.
How to take each reading correctly
- Prepare a calm setting. Sit quietly for about five minutes before measuring. Avoid talking during the test.
- Position yourself. Use a chair with back support, feet flat on the floor and your arm supported around heart level.
- Fit the cuff correctly. Put an appropriately sized upper-arm cuff on bare skin, following your monitor instructions. A cuff that is too small or too large may affect results.
- Take the first reading. Note the systolic and diastolic numbers and the time.
- Wait at least one minute. Stay seated and relaxed, then take the second reading.
- Write down both readings. Do not select only the lower or more reassuring number. Your clinician can advise how to interpret the record.
The NHS blood pressure guidance also advises a supported arm, bare upper arm and no talking while measuring.
Example seven-day blood pressure diary
Make one row for each measurement, or use two morning and two evening columns. The numbers below are fictional examples for layout only and should not be interpreted as medical advice.
| Day | Session | Reading 1 | Reading 2 | Notes |
|---|---|---|---|---|
| Monday | Morning | 126/81 | 124/80 | Seated, relaxed |
| Monday | Evening | 129/82 | 127/81 | After quiet rest |
| Tuesday | Morning | 125/79 | 123/79 | No symptoms |
Continue the same pattern through day seven. If you are following NICE's diagnostic protocol, keep day-one readings in your diary for transparency, even though they are excluded from the calculated diagnostic average.
What should you write in the notes column?
Useful context can include the date and time, whether you had symptoms, whether a reading was interrupted, and whether the cuff was repositioned. If a healthcare professional has asked you to note medicines or activities, follow their instructions. Avoid changing medication because of a home reading without professional advice.
How do you calculate the average?
When a clinician asks you to follow the NICE home-monitoring protocol to confirm hypertension, they generally use readings from days two onwards after excluding the first day's measurements. Record the actual readings first; a GP practice can check the calculation. The upper (systolic) and lower (diastolic) numbers are averaged separately. Do not average the two numbers within a single blood pressure reading.
For example, the systolic values 124, 126 and 125 have an average of 125; the diastolic values 80, 82 and 81 have an average of 81. That example illustrates arithmetic only, not a diagnosis or a complete seven-day dataset.
Which home monitor should you use?
A correctly fitting cuff and a reliable device matter. The British & Irish Hypertension Society advises using a validated upper-arm monitor. Check independent validation information for the specific model; a product being sold in the UK does not by itself establish independent clinical validation.
The Spinegear AXD-808 rechargeable upper-arm blood pressure monitor is listed with a 22–42 cm adjustable cuff, USB-C charging and two-user memory with up to 99 readings per user. These are product-listing specifications, not a claim that the model appears on a particular validation register. Confirm that the cuff fits your arm and follow the supplied instructions.
Common mistakes when keeping a blood pressure diary
- Recording just one reading: if following NICE's diagnostic protocol, take the second reading at least one minute later.
- Measuring over clothing: use the cuff on bare skin as instructed.
- Changing arm or position without noting it: ask your clinician which arm to use and be consistent.
- Only writing down high readings: record the complete set, not selected results.
- Comparing your results with someone else's: targets and clinical circumstances differ.
- Stopping prescribed treatment: do not change medicines based solely on a diary.
For more on avoiding technique errors, see our common blood pressure monitor mistakes guide and cuff sizing guide.
When should you share your readings with a clinician?
Send or bring the diary to the appointment requested by your GP or practice nurse. If you are concerned about a reading, contact your GP practice or NHS 111 rather than waiting until the end of the week. Seek emergency help for severe symptoms such as chest pain, sudden weakness or difficulty breathing; do not delay urgent care to complete a diary. The NHS reading checker offers general guidance for eligible adults but is not suitable for everyone.
Frequently asked questions
Do I have to use exactly seven days?
For NICE's diagnostic home-monitoring protocol, the minimum is four days and seven days is ideal. Your clinician may give you a different schedule.
Should I delete the first day's readings?
No. Keep them recorded. For the NICE diagnostic average, the first day is excluded from the calculation.
Can I use the monitor's memory instead of paper?
Memory can help, but check that dates, times and users are identified correctly. A written or digital diary is useful for sharing readings with a clinician.
What if my two readings differ?
Record both rather than choosing the number you prefer. Follow your clinician's instructions about repeat measurements and seek advice if you are worried.
Key takeaway
A useful seven-day blood pressure diary is consistent, complete and easy to share. Use a correctly fitting cuff, record morning and evening readings as instructed, and let your clinician interpret the pattern in the context of your health.
Sources: NICE NG136; British & Irish Hypertension Society patient diaries; British Heart Foundation blood pressure diary; NHS blood pressure reading guidance.
