Compass is still being developed and is effectively in beta. Some content and features may be incomplete, change, or not work as expected.

Content is anchored to trusted sources where available, but Compass has not yet been clinically reviewed. It provides general information rather than medical advice.

Feedback helps us identify gaps, errors, usability problems and opportunities to improve Compass over time.

How Compass is developedGive feedback

Movement and daily function

Muscle wasting

Muscle losing bulk because the nerves that supply it are no longer signalling it to work.

What it means

Muscle keeps its size partly through being used and partly through constant nerve signals. When those signals fade the muscle shrinks. It shows first where muscle sits close to the surface, such as the hand between thumb and finger.

Why you might hear it

  • It is described in examination notes as atrophy.
  • It is one of the things looked for alongside twitching and weakness.

People who may help

Where Compass goes into this

About this explanation

These are plain explanations of words you may come across, not advice about your own situation. Where a word matters to a decision, the question pages go into it properly, and your own team is the place to take it.