Starting CPAP therapy is a major step toward better sleep and long-term health. But once you're a few nights into therapy, you might start wondering whether your sleep apnea is actually getting better.
This guide will help you recognize the signs that CPAP therapy is working for you, plus what your AHI score should be after using your CPAP machine. And if you're worried you aren't getting better with treatment, we'll explain what you can do to change that.
How can I tell if CPAP therapy is working?
To know if CPAP therapy is working, check for signs like reduced snoring, fewer awakenings, and improved daytime energy. A low AHI score (under 5) also means your therapy is effective. If you're still tired or snoring, try adjusting your mask fit, pressure settings, or consult your doctor for better results.
Signs CPAP is working to improve your sleep apnea
The main purpose of a CPAP machine is to prevent airway collapse during sleep. Your device does this by delivering a steady stream of air pressure directly into your throat and upper airway.
When therapy is effective, it often leads to noticeable improvements in how you feel.
You feel more rested and alert during the day
Your snoring has improved
You don’t wake up gasping or choking for air
You wake up fewer times during the night
You no longer have morning headaches
You can think more clearly and focus better
Check your AHI score as a sign of CPAP effectiveness
One of the most reliable ways to know if CPAP is working is to track your AHI score, which stands for Apnea-Hypopnea Index.
This number tells you how many breathing disruptions (apneas or hypopneas) you have per hour of sleep. If it’s consistently low, your therapy is likely doing its job.
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You can find your nightly AHI scores on your CPAP machine’s display screen or app, along with your therapy hours and air leaks.
What is a good AHI score on CPAP?
This depends on the type of sleep apnea, but if you have mild to moderate sleep apnea, most doctors want your AHI score to fall below 5. If you have very severe sleep apnea, your doctor may aim for 10 AHI.
What Your AHI Score Means
| 0–4 AHI | Great | Below threshold for sleep apnea |
| 5–7 AHI | Good | Should improve with small tweaks |
| 8–15 AHI | Needs improvement | May need changes to treatment plan |
| 15+ AHI | Poor | CPAP not effective enough at current pressure |
Signs that your CPAP therapy is not working
If your AHI is still high, or if you’re not feeling any better after several weeks, here are signs that your CPAP machine may not be helping:
Your AHI scores are too high
Your AHI (Apnea-Hypopnea Index) measures how many breathing interruptions you have per hour. A consistently high AHI score—especially above 5—means your airway may still be collapsing during sleep.
Possible causes:
Your CPAP pressure setting may be too low to keep your airway open
You may have mask leaks, reducing effective airflow
You could be experiencing complex sleep apnea, which can actually be caused by CPAP use
In very severe cases, AHI may not drop below 5 even with therapy
You're still feeling tired during the day
Daytime fatigue is one of the top symptoms of untreated sleep apnea. If you’re still napping often or waking up groggy after weeks of therapy, something could be off.
Possible causes:
Your body may still be adjusting to CPAP therapy (this can take several weeks)
Mask discomfort may be causing micro-arousals
Inconsistent nightly use is preventing recovery sleep
Underlying health issues like restless leg syndrome or insomnia may be contributing
Most nights you are still snoring loudly
Loud or frequent snoring should decrease or disappear with effective treatment. If you're still snoring during CPAP therapy, your airway may still be partially collapsing during sleep.
Possible causes:
Air leaks around your mask are letting air escape instead of reaching your airway
Pressure may be too low to fully support your airway
You're sleeping on your back, which can worsen airway collapse
You may need a full face mask if you're mouth-breathing
You aren't dreaming
Dreaming is a sign that you're reaching REM sleep—a critical phase for memory, mood, and body repair. If you’re not dreaming at all, you may not be spending enough time during deep sleep, which happens to be the stage that is affected most with sleep apnea.
Possible causes:
Your therapy isn't fully eliminating apneas that disrupt sleep cycles
You're waking frequently without remembering it
It’s still early—REM sleep rebounds with consistent therapy
Some people naturally don’t remember dreams, even without sleep apnea
You wake up with a dry mouth, dry eyes, or sore throat
Waking up with dryness or irritation often points to airflow issues, especially around the mask or mouth.
Possible causes:
Too much air is leaking near your eyes, causing dry eye
Your humidity levels may not be high enough
Mouth breathing with a nasal mask may be causing dry mouth
Headgear may be overtightened or misaligned
Your CPAP machine is making odd noises
Unusual whirring, wheezing, or inconsistent airflow can affect sleep quality and signal equipment issues.
Possible causes:
Your machine is aging or malfunctioning
Tubing may be loose or partially disconnected
Filters or motor may be clogged
You may need to replace your CPAP machine (most last 5–7 years)
You're not using CPAP for the full night
If you take your mask off halfway through the night or struggle to wear it for more than a few hours, you’re not getting the full benefits of therapy.
Possible causes:
Mask discomfort is waking you up
You haven’t yet adapted to the sensation of pressurized air
Ramp settings may not be long enough
You need more time to build tolerance—start with short sessions and build up
What to do if CPAP therapy isn’t working for your sleep apnea
If your therapy isn’t helping, don’t give up. There are several proven ways to troubleshoot and improve your results.
Check your mask fit. A leaking or uncomfortable mask can reduce therapy quality. Try adjusting the straps or switching to a new mask style.
Train yourself to sleep on your side. Side sleeping helps keep the airway open naturally.
Fine-tune your comfort settings. Adjusting humidity, ramp time, or using EPR can make therapy more comfortable.
Replace worn equipment. Old cushions and filters can impact airflow and comfort. Refresh parts every 1–3 months.
Adjust your pressure or settings. A sleep specialist can recommend the right changes based on your data and symptoms.
When to call your doctor?
Your AHI score is consistently above 5–10
You’re using your CPAP every night but still feel exhausted
You’re experiencing new or worsening symptoms of sleep apnea
Frequently asked questions
What is a good AHI score on CPAP?
A good AHI score on CPAP is under 5 for mild to moderate sleep apnea and under 10 AHI for more severe cases of sleep apnea. If your AHI is consistently above this level, you may need to adjust your pressure settings or check for mask leaks.
Why am I still tired after using CPAP?
If you’re still tired after using CPAP, it could be due to air leaks, the wrong pressure setting, or poor mask fit. It may also take a few weeks for your body to adjust. Check your therapy data and talk to your doctor if fatigue continues.
What can I do if CPAP isn’t helping?
If CPAP isn’t helping, try adjusting your mask fit, sleeping on your side, using comfort settings like EPR or Ramp, and checking for equipment issues. You may also benefit from switching to an APAP machine or consulting your sleep specialist.
Final thoughts
Knowing if CPAP is working comes down to two things: how you feel and what your machine data shows. If you’re sleeping better, feeling more refreshed, and seeing a lower AHI score, you’re likely on the right track.
If not, don’t lose hope. Small changes to your routine, equipment, or mindset can make a big difference. CPAP therapy has helped thousands feel better —and live longer, too.
Need help? Contact us!
- Call: 1-800-356-5221
- Email: support@cpap.com
- Chat: Connectwith a CPAP Guide through our website or app
