BP Doctor Wrist Size, Cuff Fit and Common Measurement Errors

Most failed wrist BP measurements are not mysterious.

They usually come back to three things:

fit

position

movement.

Before assuming the watch is defective, check these first.

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What Wrist Size Fits Each BP Doctor?

Fit

Recommended BP wrist fit:

14–22 cm / 5.5–8.7 in

Ultra

Recommended BP wrist fit:

14–22 cm / 5.5–8.7 in

Med

Recommended BP wrist fit:

14–20 cm / 5.5–7.8 in

 

If your wrist falls outside the recommended BP range, don't assume tightening the strap more will solve the problem.

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How Tight Should It Be?

Secure.

Not painfully tight.

Fit's manual says incorrect tightness can affect the reading and stresses good contact between the air cuff and the wrist.

Too loose

Possible signs:

• cuff shifts during inflation;
• gap between cuff and wrist;
• unstable reading;
• repeated measurement error.

Too tight

Possible signs:

• discomfort before measurement starts;
• skin strongly compressed before inflation;
• difficulty positioning the cuff normally.

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What to Check When the Watch Cannot Measure

The Fit FAQ specifically tells users to check:

• whether the hand is at heart level;
• whether the strap and air cuff contact the wrist correctly;
• whether the arm is tense;
• whether the user talked or moved.

That's your troubleshooting order.

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Error Check 1 — Wrist Position

Move the watch itself to heart level.

Not just the fingertips.

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Error Check 2 — Cuff Contact

Make sure:

• no fold;
• no twist;
• no obvious gap;
• cuff is flat against the wrist.

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Error Check 3 — Arm Tension

Relax your shoulder.

Support the elbow.

Don't hold the arm up with muscle effort.

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Error Check 4 — Hand Movement

Don't:

• clench;
• flex;
• bend;
• tap the screen during measurement.

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Error Check 5 — Talking

Stay quiet from the beginning of inflation until the result appears.

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Why Does My Reading Look Too High or Too Low?

Before declaring a device problem, ask:

• Was the watch at heart level?
• Was I seated?
• Did I just exercise?
• Did I smoke or drink recently?
• Was the cuff secure?
• Was I moving?
• Did I repeat too quickly?

Fit's own troubleshooting section recommends correcting posture, wear, relaxation and stillness before escalating the problem.

If correct technique does not resolve the problem, contact support.