Still Snoring on CPAP Despite a Low AHI — What It Means

You did the work. Your CPAP report shows an apnea-hypopnea index (AHI) — the average number of breathing pauses per hour — comfortably under 5. And yet your partner still elbows you at 2 a.m., or you wake up with that dry, buzzy "I was snoring" feeling. It's confusing, but it's also one of the most fixable situations in CPAP therapy. In almost every case, snoring with a good AHI is a small, specific problem — not a sign that your treatment has failed.

This is data education, not a reason to panic. Let's walk through what the numbers are actually telling you.

Why you can snore with a low AHI

Your AHI counts complete and partial airway collapses — events where airflow stops (apnea) or drops substantially (hypopnea). Snoring is something different and milder: it's the sound of partially obstructed airway tissue vibrating while air is still moving through. You can vibrate without ever crossing the threshold that counts as an event.

That's the key insight: snoring with a low AHI usually reflects mild upper-airway obstruction that isn't progressing all the way to an apnea or hypopnea. Your pressure is doing most of its job — holding the airway open enough to prevent collapses — but not quite enough to keep every breath smooth and silent.

A few things make this even more likely:

• Device AHI is an estimate. Your machine infers events from airflow and pressure changes. It has no EEG and can't see brain arousals the way a lab sleep study can, so device-reported AHI and lab-scored AHI don't always match. A low number on your machine is reassuring but not the whole picture.
• Mild obstruction often hides between the cracks. Flow limitation and snoring are the "before" stages of an apnea. They can be present all night without ever tipping into a scored event. (See CPAP Flow Limitation: The Hidden Metric Beyond AHI for how this shows up.)
• AHI varies night to night. One quiet night doesn't mean every night is quiet, and one snore-heavy night isn't a crisis. Trends over weeks tell the real story.

So snoring on top of a low AHI isn't a contradiction. It's a signal pointing at a narrow, treatable gap.

The snore index — a recorded channel most apps bury

Here's the part most people never see. Modern CPAP machines actually record snoring as its own data channel — often reported as a "snore index" or a snore graph alongside your pressure and leak data. The machine detects the high-frequency vibration in the airflow signal and logs it.

The problem: most consumer apps don't surface this channel at all. ResMed's myAir, for example, boils your whole night down to a single 0–100 score weighted heavily toward how many hours you used the machine — it shows no event-type breakdown, no leak detail, no flow-limitation data, and certainly no snore graph. (myAir can hand you a score of 100 on a night with an AHI of 4.9.) Philips' DreamMapper was shut down in January 2026, leaving many users looking for a new home for that data. So you can be snoring with a "perfect" app score and have no way to confirm it from the app itself.

This is exactly the gap SomniCharts closes. SomniCharts imports your ResMed, Philips Respironics (including the encrypted DreamStation 2 that OSCAR and most tools can't read), and Löwenstein prisma data, then surfaces the snore channel most apps bury — in plain language — so you can see whether your snoring lines up with periods of low pressure or high leak instead of guessing. Seeing the snore graph next to your pressure and leak traces on the same timeline is what turns "am I still snoring?" into "yes, and here's why."

Under-pressure vs leak as causes

When snoring persists with a low AHI, two culprits explain the large majority of cases. The good news is that your data can usually tell them apart.

Cause 1: Under-pressure (not quite enough support)

Your prescribed pressure may be enough to prevent collapses but a notch shy of what's needed to silence the airway. This is common in people on a fixed CPAP pressure or those whose airway needs have shifted over time (weight change, aging, nasal changes).

What it looks like in your data:

• A rising or "pinned" 95th-percentile pressure — your auto-adjusting machine spending a lot of time near the top of its range, suggesting it wants more room.
• Snore events clustering during stretches where pressure is on the lower end.
• Flow limitation showing up alongside the snoring.

Important: this is a "discuss with your provider" finding, not a self-adjust one. Your data builds the case; your clinician makes the change. We'll come back to why this line matters.

Cause 2: Leak (air escaping before it can do its job)

If air is leaking from your mask or your mouth, pressure delivered to your airway drops below what your machine thinks it's giving you — and partial obstruction (and snoring) creeps back in. Leak is also why this matters beyond comfort: a large leak can invalidate or under-report your AHI, because the machine can't reliably detect events through the noise. A "low AHI" recorded during a big leak isn't trustworthy.

What it looks like in your data:

• Leak readings above the threshold during the same windows you're snoring. (ResMed flags excess leak above 24 L/min at the 95th percentile; note ResMed reports excess leak and Philips reports total leak — different baselines, so don't compare the raw numbers across brands.)
• "Mask off" or large-leak gaps in your night.
• Mouth-leak patterns if you breathe through your mouth.

Mouth leak in particular is a frequent snore driver and has tonight-level fixes. Our guides on CPAP mask leaks and mouth leak and keeping leaks in range cover the fit and chin-support fixes.

Telling them apart at a glance

What to bring to your provider

Snoring with a low AHI sits squarely in the "use your data to have an informed conversation" category. The defensible, safe move is never to dial your own pressure up to chase the snoring — it's to walk in with evidence so your clinician can make the right call quickly. (More on this boundary in Can I Adjust My Own CPAP Pressure?.)

Bring:

1. Your trend over 2–4 weeks, not a single night. Single nights are noise; patterns persuade.
2. Your residual AHI and how stable it is. For context, a residual AHI below 5 events per hour is the widely used benchmark for effective therapy (the AASM defines an "optimal" titration as getting AHI under 5). Some clinicians aim lower when it's comfortably achievable, but goals are individualized — there's no formal standard at "below 1" or "below 2." So a low AHI plus snoring is genuinely a "we're close, let's fine-tune" conversation.
3. Your snore-index trend alongside pressure and leak, so the timing relationship is visible.
4. Your 95th-percentile and median pressure, which tell your provider how hard the machine is working.
5. Your leak data — including whether any "good" nights were recorded during large leaks.

If your snoring comes with returning daytime sleepiness despite good numbers, that's worth flagging too — see Still Tired on CPAP With Good Numbers?. And if you ever see central (clear-airway) events climbing rather than snoring, that's a different conversation: CPAP reliably treats obstructive events but doesn't directly correct the unstable breathing drive behind central events, and you should never raise pressure to chase them. (We cover that in Central Apneas Showing Up on CPAP.)

Reading your snore data

You don't need to be a clinician to read the snore channel — you just need to see it on the same timeline as everything else. Here's the approach.

Look for overlap, not just totals. A snore count alone tells you little. What's diagnostic is when the snoring happened relative to your pressure and leak:

• Does snoring spike when pressure dips? → leans toward under-pressure.
• Does snoring spike when leak climbs? → leans toward leak.
• Does snoring scatter randomly with normal pressure and leak? → likely mild, possibly positional (back-sleeping) or related to nasal congestion that night.

Check the leak first, always. If a snore-heavy night also had a large leak, fix the leak before drawing any conclusion about pressure — and remember the AHI from that night may be under-reported.

Watch the trend, not the night. Two or three nights of overlapping data make a pattern. One night is weather.

This is the kind of cross-channel reading SomniCharts does automatically: it pulls your snore index, pressure, and leak into one plain-language view across multiple vendors, so the "snoring lines up with low pressure" or "snoring lines up with leak" story tells itself — and you walk into your appointment with the answer half-solved rather than a stack of raw charts. For the bigger picture of how all these numbers fit together, start with the Troubleshooting & Optimizing CPAP hub and the plain-English guide to AHI, leak rate, and pressure.

Quick FAQ

Is snoring on CPAP dangerous if my AHI is low? It's usually not dangerous on its own — it typically signals mild residual obstruction from slightly low pressure or a leak. But it's worth resolving for sleep quality, and worth checking that no large leaks are hiding a higher true AHI.

Should I turn my pressure up to stop the snoring? No — don't self-adjust prescribed pressure. Gather your snore, pressure, and leak trends and bring them to your provider, who can decide whether a pressure change is appropriate.

Why does my app say I'm doing great but I'm still snoring? Many apps (like myAir) score mostly on usage hours and don't show the snore channel at all. A high app score can coexist with real snoring; you need the actual recorded data to see it.

Can a leak make my AHI look better than it is? Yes. A large leak can prevent the machine from detecting events accurately, so a "low" AHI recorded during a big leak isn't reliable. Fix the leak, then re-read the number.