Reading Your Blood Pressure Trends and Charts

The Trend Line and Its Boundaries

The main chart draws two lines — systolic and diastolic — on one vertical scale, with horizontal reference lines at the category boundaries of whichever standard you have selected. The point is not any single dot. It is whether the lines are drifting, holding steady, or scattering more widely than they used to.

Day-to-day variation is normal and often larger than people expect. A reading that sits above a boundary on Tuesday and below it on Wednesday has not told you anything yet. Several weeks of readings clustering on one side of a boundary is a pattern, and that is the thing worth bringing to an appointment.

The free plan shows the last seven days. Premium opens the 30-day, 90-day, six-month, one-year and all-time views, which is where slow drift actually becomes visible.

Distribution, Morning and Evening

The distribution card answers a different question: not where am I now but where have I been. It shows what share of your readings landed in each category over the selected period, as a stacked bar. Two people can share an average and have completely different distributions — one steady, one swinging between bands — and the bar makes that difference obvious.

The same card reports the share of readings below the hypertension threshold, which is 130/80 under AHA/ACC and 140/90 under ESC. Because the threshold moves with the standard, the percentage moves too. It is a summary of your own readings, not a score and not a target.

Morning and evening averages are shown as separate columns, because for many people they genuinely differ. Blood pressure follows a daily rhythm, and a morning figure that runs consistently higher than the evening one is a pattern worth mentioning to your doctor rather than something to interpret yourself.

Pulse, MAP and Weight

Below the main chart, pulse gets its own sparkline. It is recorded with every reading and is a separate measurement from blood pressure — a high pulse does not imply high blood pressure, and the two can move independently.

MAP, or Mean Arterial Pressure, has a sparkline of its own. It is derived from numbers you already logged: diastolic plus one third of the gap between systolic and diastolic. BPal calculates and displays it, and explains it in the report definitions, but deliberately does not suggest a target for it. If a clinician has asked you to watch it, they will tell you what range they are looking for.

If you log weight, its trend appears on the same screen. Weight is read from Apple Health when you allow it, and BPal never writes weight back.

When a pattern in these charts looks like it is changing, the useful next step is exporting a report rather than drawing a conclusion. This guide is general information, not medical advice; your doctor interprets your readings and sets your targets.