Got AHI below 1, Still only sleep ~4-5 Hours a Night

[PikaRaichu]

Hey everyone,

(Quick note: I used ChatGPT to help clean up the grammar and layout here, but all the data, timeline, and numbers are 100% accurate.)

Hoping someone here has dealt with this and figured out a fix, because I'm hitting a wall.

August 16th

Screenshot 2026-08-16 at 7.11.16 AM.png (642.86 KiB) Viewed 8952 times

August 16th

Screenshot 2026-08-16 at 7.11.16 AM.png (642.86 KiB) Viewed 8952 times

My sleep issues started back in December 2024. I was officially diagnosed with sleep apnea in June of this year and have been on machine therapy for exactly 2 months now. I initially started out on APAP while dialing in my titration, but at the beginning of this month my doctor switched me over to fixed CPAP at 11 cmH2O after finding my ideal pressure.

The problem is the early morning awakenings. I go to bed around 9:30–10:00 PM, sleep solid until about 3:00–3:30 AM (roughly 5 hours), and then my brain just turns completely on. Falling back asleep is impossible.

For a while I was taking low-dose quetiapine off-label in the middle of the night just to knock myself out for a few more hours, but I've been totally off that for weeks now. The 4–5 hour wall remains unchanged.

Here is my current setup and data:

* **Machine:** ResMed AirSense 10 AutoSet (fixed CPAP at 11.0 cmH2O, EPR 3 / EPAP 8.0)
* **Mask:** AirFit F40 + mouth tape
* **Numbers:** AHI is consistently under 1.0 (last night was 0.82 with 0.16 OA, 0.33 CA, 0.33 H). Median leak is 7.2 L/min, under 1% time over redline. FL and snore medians are flat at 0.00.

When I look at OSCAR, the first few hours of deep sleep look super clean. Around the 4–5 hour mark, when REM hits and breathing gets more erratic, I just pop wide awake. No major leak spikes or obstructive clusters right beforehand that explain it.

A couple questions for the veteran OSCAR readers:

1. If your numbers are clinically "clean" (AHI < 1 on fixed CPAP) but you're stuck at 5 hours, was it an airway issue the machine missed (like subtle flow limitations/RERAs), or did it turn out to be sleep maintenance insomnia / circadian?
2. Anything specific in the flow rate waveform I should zoom in on right before the wake-up?

Posting my OSCAR daily summary and flow rate graphs below. Appreciate any feedback or ideas on what to try next.

[Pugsy]

You can resize the graphs so that you can get the flow limitations included in one screen shot and no need to do separately.

Are you having any nasal congestion at night? Sometimes FLs will be increased because of nasal issues and cpap can't fix those. You would need to address the nasal congestion in the more traditional ways to fix that problem if you are having nasal congestion.

Did you have this sleep pattern of waking after 4 or 5 hours sleep with the inability to fall back to sleep prior to starting cpap? Maybe this sleep issue is unrelated to the apnea issue.

Did you know that it's normal to wake after a REM cycle and before that 4 or 5 hour time frame you probably had 2 or 3 other REM cycles that you don't/or didn't wake up after?
Obviously not being able to go back to sleep is unwanted in your case.
It's called sleep maintenance insomnia and it's a real bitch. Believe me I suffer from it myself but it's related to other health issues and nothing to do with apnea issue.
It's really hard sometimes to figure out the why and even then not always so easy to fix. Been there and done that myself.

[Sleepzilla]

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[PikaRaichu]

You can resize the graphs so that you can get the flow limitations included in one screen shot and no need to do separately.

Are you having any nasal congestion at night? Sometimes FLs will be increased because of nasal issues and cpap can't fix those. You would need to address the nasal congestion in the more traditional ways to fix that problem if you are having nasal congestion.

Did you have this sleep pattern of waking after 4 or 5 hours sleep with the inability to fall back to sleep prior to starting cpap? Maybe this sleep issue is unrelated to the apnea issue.

Did you know that it's normal to wake after a REM cycle and before that 4 or 5 hour time frame you probably had 2 or 3 other REM cycles that you don't/or didn't wake up after?
Obviously not being able to go back to sleep is unwanted in your case.
It's called sleep maintenance insomnia and it's a real bitch. Believe me I suffer from it myself but it's related to other health issues and nothing to do with apnea issue.
It's really hard sometimes to figure out the why and even then not always so easy to fix. Been there and done that myself.

Hi Pugsy,

I started having these wake up issues back in December 2024, so yes prior to starting CPAP.

I actually fought like hell with my partner not to go to a sleep specialist because I didn't want to be believe I had SA. I exhausted all options before: ENT, Physio, Mental health, Neurologist, etc.

Regarding the nasal congestion, I visited an ENT to check my nasalcavities, and also several hours with a respiratory physiotherapist who gave me a great nasal clearing routine at night so I’m good there.

Now that I have gotten the Apneas under control, I wanted to reach out to you all for advice. I will look into SMI, that you mentioned. Thank you

[PikaRaichu]

The problem is the early morning awakenings. I go to bed around 9:30–10:00 PM, sleep solid until about 3:00–3:30 AM (roughly 5 hours), and then my brain just turns completely on. Falling back asleep is impossible.

When I look at OSCAR, the first few hours of deep sleep look super clean. Around the 4–5 hour mark, when REM hits and breathing gets more erratic, I just pop wide awake. No major leak spikes or obstructive clusters right beforehand that explain it.

Appreciate any feedback or ideas on what to try next.

Welcome to the club. See my comments and a couple external links to discussion of sleep maintenance insomnia in this recent thread on a similar topic.

Hello! thanks for the links. I checked them out, and it's definitely not an easy problem to fix.
Wouldn't wish this on my worst enemy lol.

[Craig H]

Apart fom the "awakening" issue....how do you actually feel since you began sleep therapy?

Has there been a change to how you feel and do the stats you posted, show an improvement from your test results?

FWIW...I usually have a more conscious period (semi awake) every night around about similar to your times (I think...without checking)...but I always go back to sleep until alarm time.
It does not worry me and I continue to get AHI results that satisfy me despite them being nothing as good as your. 0.82AHI.
Key to me is how I feel during the subsequent day...and that is ...GREAT ( no apnoea effects like drowsinesss, fog or dropping asleep).

BTW...I use certain relaxation and mind techniques to help sleep.

[PikaRaichu]

Apart fom the "awakening" issue....how do you actually feel since you began sleep therapy?

Has there been a change to how you feel and do the stats you posted, show an improvement from your test results?

FWIW...I usually have a more conscious period (semi awake) every night around about similar to your times (I think...without checking)...but I always go back to sleep until alarm time.
It does not worry me and I continue to get AHI results that satisfy me despite them being nothing as good as your. 0.82AHI.
Key to me is how I feel during the subsequent day...and that is ...GREAT ( no apnoea effects like drowsinesss, fog or dropping asleep).

BTW...I use certain relaxation and mind techniques to help sleep.

I feel slightly better, but not as good as someone who can sleep a full 8 hours.
My AHI during my study was 17, so definitely an improvement.
I do not feel GREAT at all, just slightly better than I did without using CPAP. I still can't exercise and be as active as I'd like to be so that is why I’m here to look for answers.

[bran]

Just a suggestion. Take 2 Diphenhydramine 25mg tablets about 20 minutes before bed. Purchase OTC. I read in bed first. When you feel your eyes closing, mask on and go to sleep. See how long you can sleep for. Failing that 1 before bed, wake and then another. It's not habit-forming. My issue is that I tend to go to bed very late, just the nature of the beast, even though I have tried the "normal times". I sleep for 3 hours. Events under 1 which is huge for mew and leaks controlled. But i wake up to pee after 3 hours. Sometimes I go back to sleep and sometimes I don't until 6-7 in the morning, and luckily I'm retired so can afford to sleep which I do until 11.30to 12, but that's not good for me, I know. Wasting away the day. However, the pills have helped, and I'm off all prescribed sleeping pills as they were ruining my life and I became addictive.

In total, I get over 8 hours of sleep, on the other hand some of us only need 6 hours anyway?

Found that the Brand Reliable 1 Amazon under $8.00 for 100 works the best and fastest. I feel drowsy in under 15 mins. When I used to have 6-hour infusions for my MG they told me to take the pills beforehand with the objective to calm me down, make me relaxed and sleepy. It worked.

[Pugsy]

Just a word of caution about taking Benadry/Diphenhydramine to help with sleep.
Make sure you don't have any medical issues that would make benadryl contraindicated so check with you doctor first.
It's fairly benign but there health issues where it's not a good idea to be taking Benadryl.

BTW I also take the benadryl at bedtime to help me sleep because I have some arthritis pain issues that wake me up often and I have hypertension and it doesn't seem to mess with my BP and it does help me sleep a little longer most of the time.
It can dry the mouth though so be aware of that little annoyance.

[Grumpy48]

I remembered reading your post from a couple days back and this afternoon the video below popped up on my Youtube feed. My nightly routine consists of a Magnesium Glycinate tablet just after supper which helps muscles relax and supposedly helps with sleep. At about 9:00pm before settling in for a couple Netflix shows I take a dropper of a CBD/CBN tincture which is formulated to help sleep. While watching Netflix I have a light snack with a cup of Chamomile tea to which I've added 3 grams of Glycine powder (also a sleep aid). Hit the bed at 11:00pm.
Your issue may not be cortisol, but maybe something to consider.

https://www.lazarusnaturals.com/product ... l-tincture (Veterans discount available)
https://www.amazon.com/dp/B000BD0RT0
https://www.amazon.com/dp/B09F83CPX8?th=1

https://youtu.be/uYvEK3GTD6M

[bran]

Just a word of caution about taking Benadry/Diphenhydramine to help with sleep.
Make sure you don't have any medical issues that would make benadryl contraindicated so check with you doctor first.
It's fairly benign but there health issues where it's not a good idea to be taking Benadryl.

BTW I also take the benadryl at bedtime to help me sleep because I have some arthritis pain issues that wake me up often, and I also have hypertension, and it doesn't seem to mess with my BP, and it does help me sleep a little longer most of the time.
It can dry the mouth though so be aware of that little annoyance.

Good advice. I have Myasthenia Gravis but under control. Doc told me it's ok just don't take it every night, It's certainly better than Ambien, that did my head in. Yep Hypertension, arthritis, and need an arthroscopy as ankle pain due to past fractures, is what is actually keeping me awake with the pain. Great fun getting older. Not. But many here helped me greatly in the early days and so grateful and to those who sleep, wake, mask off and mask on, etc, etc. I was exactly the same, leaks, mask not fitting, went through it all. Absolutely hated the damn thing. Went through every mask going right up to the bleep thingy(just couldnt cope with that)Gradually and as many stated here, perseverance and now, I don't feel comfortable without it, in fact i can't breath as well, my nose gets blocked without it??. Events around 1-1.5, sometimes under 1. Leaks under 4. They were over 10-15 and leaks over 24. Took about a year to 18 months and sometimes early in the morning I do take it off for a few hours as my nose a bit sore(but have interesting dreams, see below. Interesting also that after I had a pacemaker fitted in April the events and leaks went right down. Co-incidence? Don't know.

p.s. Is it just me, but I don't dream as much these days with the mask on, when off I do???? Or am I really on the verge of senility.

[Pugsy]

Is it just me, but I don't dream as much these days with the mask on, when off I do???? Or am I really on the verge of senility.

Actually not remembering a bunch of dreams is a good thing.
We can dream in any sleep stage. It's not limited to REM.
We won't remember a dream unless we wake up during the dream so if we don't wake up we won't remember a dream.
So not remembering is actually a good thing because it means we are sleeping more soundly.

If you sleep without the mask being on (which is a bad thing to be doing) then the apneas you have are waking you up during the dream and wake ups are a bad thing and why we want to prevent the apnea by using cpap.