“I sleep 7–8 hours now.
My AHI is great.
But I actually feel worse than when I slept less.”
This complaint appears constantly on Reddit, often followed by confusion, self-doubt, and eventually frustration with CPAP itself.
The assumption is simple:
More sleep + low AHI = better results
But sleep physiology doesn’t work that way.
1. Longer Sleep Exposes Problems Short Sleep Can Hide
When sleep duration increases:
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REM sleep expands
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Light sleep becomes more fragmented
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Sensory awareness increases
Shorter sleep often ends before cumulative discomfort becomes noticeable.
Longer sleep gives CPAP more time to irritate, not more time to heal.
This is why users often report:
“I felt better when I only slept 5–6 hours.”
Reference:
Carskadon MA, Dement WC. Normal human sleep. Principles and Practice of Sleep Medicine.
2. REM Sleep Makes CPAP Discomfort More Noticeable
REM sleep:
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Occurs more frequently in the second half of the night
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Is lighter and more arousal-prone
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Involves irregular breathing patterns
During REM:
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Mask leaks are more disruptive
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Pressure changes feel harsher
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Breathing resistance is perceived more strongly
AHI may remain low, but REM-related micro-arousals increase.
Reference:
Jordan AS, McSharry DG, Malhotra A. Adult obstructive sleep apnoea. The Lancet.
3. AHI Does Not Measure Sleep Fragmentation
AHI only counts:
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Apneas
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Hypopneas
It does not measure:
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Respiratory effort–related arousals (RERAs)
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Sensory awakenings
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Pressure-response disturbances
So it’s entirely possible to have:
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AHI < 1
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Dozens of micro-arousals
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Poor perceived sleep quality
Reddit users often say:
“My data is perfect, but my sleep feels worse.”
They’re right.
Reference:
Berry RB et al. Rules for scoring respiratory events. AASM Manual.
4. The “Last Third of the Night” Problem
Sleep architecture is not evenly distributed.
In the final third of the night:
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REM dominates
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Arousal threshold drops
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CPAP-related disturbances peak
Common complaints during this phase:
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“Air feels harsher toward morning”
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“I wake up exhausted after long nights”
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“CPAP feels fine early, awful later”
Nothing is “breaking” — the system is simply revealing its weakest points.
5. Cumulative Exposure Amplifies Minor Issues
CPAP discomfort behaves like dose-dependent exposure.
The longer you sleep, the more:
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Dryness accumulates
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Pressure sensations add up
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Small leaks repeat
Eight hours of slightly annoying airflow is worse than five hours of the same thing.
This explains why:
Longer sleep ≠ better sleep
when comfort factors are unresolved.
Reference:
Stepanski EJ. The effect of sleep fragmentation. Sleep.
6. Why This Feels So Confusing for Users
Users are told:
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“Sleep more”
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“Your AHI is excellent”
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“CPAP is working perfectly”
Yet subjectively they feel worse.
This mismatch causes:
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Anxiety
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Over-fixation on data
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Distrust of their own experience
Eventually, many conclude:
“CPAP just doesn’t work for me.”
In reality, the therapy works—but the experience doesn’t.
7. Clinical Interpretation
From a sleep-medicine perspective, this pattern suggests:
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Apnea control without comfort optimization
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Residual sleep fragmentation
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REM-sensitive intolerance
It is not a failure of CPAP as a treatment.
It is a failure to address long-duration usability.
Conclusion
If CPAP feels worse when you sleep longer—even with a low AHI—this does not mean:
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You’re imagining it
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You’re regressing
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CPAP stopped working
It means longer, more natural sleep is exposing unresolved micro-disturbances that short sleep never revealed.
Until those are addressed, sleeping more can genuinely feel worse.