Blood Pressure Checker & Log

About the Blood Pressure Checker & Log

Type one or several readings from your monitor — systolic (the top number), diastolic (the bottom number) and, if you like, your pulse — and the checker averages them and tells you the category under the guideline you choose: the 2025 AHA/ACC guideline (normal, elevated, stage 1, stage 2), the 2024 ESC guideline (non-elevated, elevated, hypertension) or the 2020 ISH guideline (normal, high-normal, grade 1, grade 2). Home readings are judged against the lower home thresholds. It also shows pulse pressure and mean arterial pressure, compares the three guidelines, and flags a very high reading with what to do.

The optional home log follows the European home-monitoring protocol: morning and evening sessions of two readings for up to 7 days, with the first day left out of the average. It draws your trend and makes a PDF report for your doctor — the home average, a trend chart with your notes (such as a medication change) marked on it, weekly averages for logs that run over weeks or months, and every reading — or a CSV. The log stays in this browser — only if you choose to keep it — and is never uploaded.

The categories

• 2025 AHA/ACC (unchanged from 2017): normal below 120 and below 80; elevated 120–129 and below 80; stage 1 hypertension 130–139 or 80–89; stage 2 140 or more or 90 or more. When systolic and diastolic fall in different categories, the higher one applies. Severe hypertension is a systolic above 180 and/or a diastolic above 120; with signs of acute organ damage it is a hypertensive emergency.
• 2024 ESC: non-elevated below 120/70; elevated 120–139 or 70–89; hypertension 140/90 or more. A hypertensive emergency must be ruled out at 180/110 or more.
• 2020 ISH: normal below 130 and 85; high-normal 130–139 and/or 85–89; grade 1 hypertension 140–159 and/or 90–99; grade 2 160 or more and/or 100 or more.
• Home thresholds: home readings run lower than clinic readings. A home average of 135/85 corresponds to a clinic 140/90 in all three guidelines; the ACC/AHA table keeps 120/80 and 130/80 the same at home and in the clinic, and ESC keeps 120/70.
• Pulse pressure = systolic − diastolic. Mean arterial pressure (MAP) ≈ diastolic + ⅓ × pulse pressure.
• Low blood pressure: the NHS calls a reading of less than 90/60 mmHg low; it only needs attention if it causes symptoms such as dizziness or fainting.

How to measure (home protocol)

• Use a validated upper-arm monitor with the right cuff size. Wrist monitors are more prone to errors, and cuffless devices such as smartwatches are not recommended for diagnosis.
• Sit for 5 minutes in a quiet room with your back supported, feet flat, arm resting at heart level and bare (don’t roll up a tight sleeve), without talking. Avoid exercise, caffeine and tobacco for 30 minutes before, and empty your bladder if needed.
• Take two readings 1–2 minutes apart, in the morning (before breakfast and before blood pressure medicines) and the evening, for at least 3 and ideally 7 days before a clinic visit.
• Average all the readings. The ESH and ISH protocols leave out the first day, which tends to be higher; the ESH 2021 paper says the need to discard it “is matter of debate” and ESC 2024 averages all days, so the log lets you switch it off.
• Once your blood pressure is controlled, a week of readings before each visit is usually enough — daily measuring is discouraged.

Your data

Readings you check at the top are not stored anywhere. The home log is kept in memory on this page until you tick Keep my log in this browser — then it is saved in this browser’s local storage under tv-pref-blood-pressure-checker, on this device only (also listed on the cookies and storage page). Delete log removes it. CSV and PDF files are created on your device; Import CSV reads a file exported here, for example to move your log to a new phone.

Sources

• Jones DW, Ferdinand KC, Taler SJ, et al. 2025 AHA/ACC multisociety Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults. Hypertension 82(10):e212-e316 — categories as reviewed in Giacona JM, Vongpatanasin W. Curr Cardiol Rep 2026;28:90 and Brown C, Clark D, Jones DW. Curr Hypertens Rep 2026;28:19
• Whelton PK, Carey RM, Mancia G, et al. Harmonization of the ACC/AHA and ESC/ESH blood pressure guidelines. Eur Heart J 43:3302-11 (Table 2: ACC/AHA clinic–home equivalents)
• McEvoy JW, McCarthy CP, Bruno RM, et al. 2024 ESC Guidelines for the management of elevated blood pressure and hypertension. Eur Heart J 45:3912-4018 (Table 5, Figures 3–4, section 10.1.1)
• Unger T, Borghi C, Charchar F, et al. 2020 International Society of Hypertension Global Hypertension Practice Guidelines. Hypertension 75:1334-57 (tables as in the ISH guideline slide set)
• Parati G, Stergiou GS, Bilo G, et al. Home blood pressure monitoring: a 2021 position paper of the ESH Working Group. J Hypertens 39(9):1742-67 (Boxes 15–16)
• DeMers D, Wachs D. Physiology, Mean Arterial Pressure. StatPearls · NHS. Low blood pressure

Limitations

• A category from a few readings is not a diagnosis: hypertension is confirmed with repeated readings on different days, ideally at home or with a 24-hour monitor.
• The thresholds are for adults who are not pregnant. Pregnancy, children and some conditions (such as kidney disease or diabetes) have different targets.
• Readings must be 50–300 systolic and 25–200 diastolic, with the diastolic lower; pulse 25–250. The log holds up to 1,000 readings and notes of up to 120 characters.
• The PDF uses a standard font, so notes in non-Latin scripts appear as “?” in the PDF; the CSV keeps them.

Privacy

Readings are processed in your browser and never sent anywhere. The home log is kept only if you tick “Keep my log in this browser”, in local storage on this device; “Delete log” removes it, and CSV/PDF exports are files you download yourself.