semiatic
OK

Cuff fit check (cuff too loose or too tight)

The monitor checks how the cuff sits on your arm. The plain cuff symbol means it is fitted well enough; the changed icon means it is too loose, too tight or out of place.

Check your monitor’s manual — makers differ.

What it is for

Refit the cuff on the bare upper arm, snug but not tight, with the artery mark over the artery; Microlife says “2-3 cm above your elbow”. Microlife: “If the icon [suboptimal cuff fit] appears, the cuff is fitted suboptimally, but it is still ok to measure.” Beurer (BM 28): “Apply the cuff correctly and take a new measurement.”

These pages report what each maker’s manual says and quote it wherever health is involved. They do not diagnose anything and are not medical advice; only your own monitor’s manual describes your model.

What it looks like
A drawing of the arm cuff — a band with its air tube — shown during or after the measurement, with an extra mark or a changed icon when the fit is wrong.
Names makers use
Cuff Fit Check (Microlife); Cuff position control (Beurer); ERROR 201 (Withings, as text)

Where makes differ

Microlife still measures with a suboptimal fit but leaves those readings out: “Blood pressure readings with suboptimal cuff fit are not considered in the average value.” Beurer’s BM 28 shows the cuff position control symbol “throughout the entire measurement”, and if the cuff is too tight or too loose it cancels the measurement after about 5 seconds and switches off. Withings has no icon and writes ERROR 201: “The cuff is not tight correctly.”

What it does not mean

It does not check that the cuff is the right size for your arm. Both makers tell you to pick the cuff by arm circumference — Beurer: “Only use the device with the cuff supplied, based on your upper arm circumference”; Microlife lists cuff sizes from S (17–22 cm) to L–XL (32–52 cm).

Sources

No published standard we could check defines blood pressure monitor control icons, so this meaning is taken from 3 makers’ own manuals and support pages, each fetched and read on the date shown:

Written in our own words; quotations are the makers’ wording.