Read them in this order, because each one only means something if the one before it is in place. 1. Usage — did the machine get the chance? Hours per night and nights per week. Most of the other numbers are averaged over the time the mask was on, so two hours of perfect data is still two hours. The usual clinical and insurance yardstick is four hours on most nights; the therapy yardstick is all of your sleep. How to Read CPAP Usage Hours and What 'Compliant' Really Means 2. Leak — could the machine do its job? A mask that leaks heavily cannot hold pressure, and the machine stops being able to tell what your airway is doing. Look at how long the night spent in large-leak territory, not the peak number — a thirty-second roll-over blip is noise; forty minutes is a fitting problem. Each brand reports leak differently (ResMed shows excess leak, Philips shows total leak), so compare against your own machine's scale. CPAP Leak Rate: What's Acceptable and How to Fix High Leaks 3. AHI — what was left over. Events per hour of use. The convention most clinicians use is "under 5 is treated", and most people on well-fitted therapy sit well under that. Two things matter more than any single night: the trend over a couple of weeks, and the spread — a quiet 1.2 one night and 6 the next says "something was different that night" (position, alcohol, a cold, a leak) more than it says "the therapy is failing". If the events are mostly clear airway rather than obstructive, that is a separate conversation worth having with your clinician. What Is a Good AHI on CPAP? AHI Ranges and Residual AHI Explained 4. How you feel. Not a number, but the point. Good numbers and a bad morning is a real and common pattern with its own list of causes. Still Tired on CPAP With Good Numbers? Reasons and Next Steps What we will not do here is tell you what your pressure should be. The three numbers above, over two weeks, are exactly what to bring to the person who can. Nothing on SomniTalk is medical advice. Talk to your own clinician before changing therapy.