Can Blood Pressure Machine be Wrong

Blood pressure machines can indeed give faulty readings. Causes include user error, device calibration, cuff size or placement, and physiological factors. Here’s a concise guide to help you assess and improve accuracy.

Core ways a BP monitor can be wrong

• User error

  • Cuff too loose or not at heart level

  • Speaking, recent exercise, caffeine, or nicotine before measurement

  • Not resting for several minutes prior to measurement

• Device issues

  • Poor calibration or aging components

  • Inaccurate cuff size for arm circumference

  • Sensor or pump malfunctions in automated devices

• Physiological factors

  • Recent meals, stress, pain, or dehydration

  • Atrial/arterial conditions that affect readings

Tips for reliable home measurements

• Use the correct cuff size: measure your arm and choose a cuff that fits snugly with the inflatable bladder covering about 80% of the arm’s circumference.

• Position properly: seated with back supported, feet uncrossed and flat, arm supported at heart level, cuff on bare skin.

• Take multiple readings: 2–3 readings one minute apart, and use the average.

• Standardize timing: measure at the same times each day, ideally after 5 minutes of rest and before caffeine or smoking.

• Check the device: ensure batteries are fresh, or it’s plugged in; verify cuff calibration against a clinician’s device if possible.

• Compare with clinic readings: if your home readings consistently differ by 10–15 points or more from your clinician’s measurements, have the device and technique reviewed.

When to seek professional guidance

• Readings remain consistently high (e.g., systolic ≥140 or diastolic ≥90) across multiple days and times.

• You notice sudden, unexplained changes in readings.

• A clinician questions your home monitor’s accuracy or you have a cuff-related pain or symptoms.