High Leak Rate
ResMed CPAP Machine
Severity: ModerateWhat Does This Error Mean?
A high leak rate means too much air is escaping from your mask rather than being delivered to your airway. Therapy is less effective. The fix is almost always adjusting the mask fit.
Affected Models
- ResMed AirSense 10 AutoSet
- ResMed AirSense 11 AutoSet
- ResMed AirCurve 10
- ResMed AirMini
- All ResMed CPAP machines with myAir reporting
Common Causes
- Mask not fitted properly to the face
- Mask cushion worn out or hardened
- Wrong mask size
- Mouth breathing while using a nasal mask (mouth leak)
- Facial hair interfering with the seal
- Sleeping position causing the mask to shift
How to Fix It
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Re-fit your mask while lying in your sleep position.
Most people fit the mask while sitting upright. The face changes shape when lying down — fit it in your actual sleeping position for a better seal.
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Check the mask cushion for wear.
Silicone cushions should be replaced every 1–3 months. A flattened or tacky cushion will no longer seal properly. ResMed sells replacement cushions for all mask models.
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Adjust the headgear — aim for firm but comfortable.
Over-tightening actually worsens leaks by distorting the cushion. The cushion needs enough pressure to seat evenly, not to be clamped.
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If you breathe through your mouth, add a chin strap or switch to a full-face mask.
Mouth breathing bypasses a nasal mask completely — all the pressure escapes from your mouth. A full-face mask (covering nose and mouth) solves this.
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Try a different mask size or style.
ResMed offers free mask fitting guidance on their website and via sleep clinics. If you have facial hair, a mask with a nasal pillow design often seals better.
Frequently Asked Questions
What leak rate is acceptable on a ResMed CPAP?
ResMed considers an unintentional leak rate under 24 L/min acceptable. Above this threshold it is flagged as a high leak. Some intentional leak (from the mask vent) is normal and expected — the machine accounts for this.
Will a high leak rate affect my AHI score?
Yes — high leaks can cause the machine to inaccurately report events (false apnea detections) and reduce actual therapy pressure. Fixing the leak typically lowers your AHI.