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Breathing and ventilation

Respiratory failure

The point at which breathing is no longer doing enough of its work without support, usually because the muscles have weakened rather than because the lungs are damaged.

What it means

A clinical description rather than a sudden event. It means breathing is no longer moving enough air in and out. In ALS/MND that is usually because the breathing muscles have weakened, not because the lungs themselves are damaged. That is why the support offered is help with breathing rather than oxygen alone. It can come on slowly over months, and is often recognised from tests before it is obvious day to day.

Why you might hear it

  • It appears in clinic letters and hospital notes.
  • It is the state NIV is offered to prevent or relieve.

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.