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

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Breathing and ventilation

CPAP

Continuous positive airway pressure

One steady pressure that holds the airway open, used mainly for sleep apnoea rather than for weak breathing muscles.

What it means

The machine blows air at a single constant pressure. That holds open an airway that would otherwise close during sleep, which is what obstructive sleep apnoea needs, but it does not help a weak muscle pull a breath in. The two kinds of machine look similar.

Why you might hear it

  • Somebody may already own one for snoring or sleep apnoea and wonder whether it will do.
  • A team may explain why they are recommending NIV instead.

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.