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Part ofHow to Read CPAP Data
GUIDE · 5 MIN READ
How to lower your AHI on CPAP
If your AHI is higher than you expected on CPAP, the cause is usually something you can see in your data: a leak that hides events, a mask that does not seal, sleeping on your back, a pattern of central events or a pressure range that is too narrow. You can fix some of these yourself. The pressure settings are for your clinician, so the goal is to arrive with clear data and a specific question.
First, what counts as high
Your machine's AHI is the average number of apneas and hypopneas per hour of therapy. Untreated bands are usually 5 to 15 mild, 15 to 30 moderate and above 30 severe, and most people on CPAP aim to stay under 5. A single night above 5 is normal; what matters is the 30-night trend. See What is AHI? and What is a good AHI on CPAP?.
The common reasons
Leak
A leaking mask lets pressure escape and makes events harder for the machine to detect, so leak and AHI have to be read together. A low AHI with high leak may be a night the machine could not see well, and a high AHI with high leak may be leak, not airway. Start with CPAP leak rate, explained and mask leaking fixes.
Mask fit and mouth leak
A mask that moves when you turn over, or air escaping through an open mouth, both disturb therapy. Mouth leak shows as a plateau in the leak graph and a dry mouth on waking.
Sleep position
Many people have more events on their back. If your high-AHI nights cluster on nights you slept supine, tell your clinician. Sleeping on your side often reduces events, and the mask style that suits side sleepers is covered in the best CPAP mask for side sleepers.
Central events
Some apneas are central: the airway is open but breathing effort pauses. More pressure does not help those, and in a minority of people higher pressures can bring them on. If your event composition shows a growing share of central events, that is a clinician conversation. See Central vs obstructive apnea on CPAP.
Pressure range
On an auto machine, a 95th-percentile pressure sitting at the ceiling night after night means the machine wanted more pressure than it was allowed. Whether to raise the range depends on leak, event type and symptoms, so raise it with your clinician. See P95 pressure in plain English.
Everything else
Alcohol, sedatives, nasal congestion, a recent weight change and a new mask all move AHI. Note them on the night they happen.
What to do this week
Read AHI and leak together
on the same nights in Trends.
Note your position and any changes
(new mask, cold, alcohol) for a week.
Look at event types
, not just the total.
Check P95 pressure against your set range.
Fix anything simple first:
refit lying down, replace a worn cushion, manage the hose.
What to bring to your clinician
A 30-night AHI trend, leak P95, pressure P95 against your range, the share of central events if your machine reports it, and a short list of what changed. A one-page report helps; see Sharing your CPAP data with your doctor. Do not change your pressure or mode yourself.
Questions people ask
Why is my AHI high on CPAP?
Common reasons are leak, a poorly sealing mask, back sleeping, central events and a pressure range that is too narrow. Look at leak first because it affects how reliable the AHI is.
What is a good AHI on CPAP?
Most people aim for under 5 events per hour on average. A few higher nights are normal. A sustained rise is worth raising with your clinician.
Can I raise my own CPAP pressure to lower my AHI?
No. Pressure settings are a prescription, and changing them without guidance can leave events untreated or provoke central apneas.
Does a low AHI mean my CPAP is working?
Usually, but read it with leak and symptoms. A low AHI on a high-leak night may be the machine failing to see events.
How long should I wait before worrying about my AHI?
Look at a 30-night trend rather than single nights. If it stays above target, or you feel unwell despite a low AHI, contact your clinician.
Ready for a clearer picture of your nights?
The web app is live today. iPhone and iPad are on the App Store. Android is on Google Play. Your first 30 nights are free, forever.
Not medical advice. Apnealytics is a tracking and coaching tool, not a diagnostic device. Machine-estimated numbers are not a clinical diagnosis — always talk to your clinician about your therapy and before you change any setting.
