You’ve been using your CPAP faithfully, maybe for years, and lately something feels off. You’re waking up tired again, your partner says the snoring is back, or you just don’t feel like the machine is doing what it used to do. Before you assume something is broken or that your sleep apnea is getting worse, it helps to know that this is a common and usually solvable situation, and there’s a clear path for figuring out what’s actually going on.
This guide walks through what to check yourself first, the signs that point to something more than a quick fix, and when it’s time to talk to a sleep specialist about a repeat sleep study or a re-titration.
Rule Out the Simple Fixes First
Not every case of “my CPAP isn’t working” means your treatment has failed. Equipment issues are common and often easy to resolve without a new sleep study at all. Before assuming you need to see a specialist, it’s worth checking:
- Mask fit and seal. A mask that fit well a year ago may not fit the same way now, especially after weight changes or normal wear on the cushion. Air leaks around the mask reduce how well the pressure reaches your airway.
- Filters. A dirty or clogged air filter makes the machine work harder and can change how the air feels, even without changing the actual pressure setting.
- Humidifier settings. Too little humidity can cause dryness and discomfort that feels like the therapy “isn’t working,” even when the pressure itself is fine.
- Tubing and connections. Cracks, kinks, or a poor connection between the tubing and the mask or machine can cause leaks that aren’t always obvious.
- Hours of use. If you’re not wearing the mask the full night, or removing it partway through, you may not be getting enough consistent therapy for it to feel effective, regardless of the pressure setting.
If you’ve checked all of this and things still don’t feel right, that’s a meaningful signal, not everything is a mask or filter problem.
Why CPAP Effectiveness Can Change Over Time
It can feel confusing when a treatment that worked well for years suddenly seems less effective, especially if nothing about your routine has obviously changed. A few physiological reasons this happens:
- Airway anatomy shifts with weight. Even modest weight gain can add tissue around the throat that narrows the airway further, meaning the same pressure that once kept it open may no longer be enough.
- Aging changes muscle tone. The muscles that support the airway naturally lose some tone over time, which can gradually shift how much pressure is needed.
- New medications can affect breathing. Certain medications, including some muscle relaxants, sedatives, and opioid pain medications, can affect respiratory drive or muscle tone in ways that alter how your body responds to a given pressure setting.
- Other health conditions can emerge. Conditions like hypothyroidism or heart failure can independently affect sleep-disordered breathing, layering a new factor on top of your original diagnosis.
None of this means your original titration was wrong. It means the setting that was right for your body at one point in time may not be the right setting for your body today, which is exactly the kind of change a re-titration is designed to catch.
Signs Your CPAP May No Longer Be Working as Well as It Should
A few patterns tend to show up when the issue goes beyond equipment maintenance:
- Daytime sleepiness or fatigue creeping back in, even with consistent CPAP use
- Snoring returning, according to a partner, despite wearing the mask
- Morning headaches that weren’t there before
- Waking up gasping or with a racing heart
- Feeling unrefreshed no matter how many hours you spend using the machine
None of these automatically mean you need a new sleep study. But they’re the signals worth bringing to a sleep specialist rather than assuming they’ll resolve on their own.
When a Repeat Sleep Study or Re-Titration Is Actually Needed
The American Academy of Sleep Medicine (AASM) published a clinical guidance statement in 2021 specifically addressing when follow-up sleep testing is appropriate for people already being treated for obstructive sleep apnea. It lays out several specific situations, and it’s worth knowing what they actually are, rather than assuming routine retesting is standard.
Your Symptoms Have Returned Despite Good Adherence
If you’re using your CPAP consistently, meaning you’re actually wearing it most of the night, most nights, and your symptoms are still returning, that’s one of the clearest indications a re-evaluation is appropriate. The AASM guidance is specific here: this applies to symptoms returning despite good adherence, not simply feeling like therapy could be more comfortable.
Your Machine’s Own Data Is Showing a Problem
Modern CPAP machines track data like your residual AHI (how many breathing events are still happening despite treatment) and how much air is leaking around your mask. If your machine’s data shows an elevated residual AHI, especially alongside returning symptoms, that’s a specific reason the AASM guidance points to for considering follow-up testing. This is also relevant if your data suggests a pattern consistent with treatment-emergent central sleep apnea, a different type of breathing disruption that can develop after starting CPAP and sometimes requires a different treatment approach entirely. This particular pattern needs to be evaluated by a specialist, not interpreted from the home data alone.
You’ve Had a Significant Change in Weight
Body weight has a well-documented effect on the airway, and a significant change in weight since your last sleep study, in either direction, can shift how much pressure your body actually needs. A pressure setting that worked well before may now be too high or too low. If your weight has changed meaningfully since you were first titrated, this is worth raising with your sleep specialist rather than assuming your symptoms are unrelated.
You’ve Had a Change in Heart Health
Conditions like newly diagnosed high blood pressure that isn’t responding to treatment, a new heart rhythm problem, heart failure, or a stroke can all interact with sleep apnea in ways that weren’t part of the picture at your original diagnosis. The AASM guidance specifically supports follow-up testing in these situations, since the relationship between sleep apnea and cardiovascular health can change over time.
You’ve Switched to a Non-CPAP Treatment
If you’ve moved to an oral appliance, positional therapy, or a surgical treatment for sleep apnea, follow-up testing is actually recommended, not just an option, according to the AASM guidance. Unlike a CPAP machine, these treatments don’t generate their own nightly data, so a follow-up sleep study is the only reliable way to confirm they’re actually controlling your sleep apnea.
Signs of Low Oxygen or Breathing Changes During Sleep
In some cases, particularly for people with underlying heart or lung conditions, oxygen levels can remain low during sleep even after starting CPAP therapy. This isn’t always something you’d notice on your own, which is part of why the AASM guidance supports follow-up testing to check for this specifically in patients with relevant health conditions.
When You Likely Don’t Need a Repeat Study
This is worth stating plainly, because it’s easy to assume more testing is always safer: if you’re using your CPAP consistently, your symptoms are well controlled, and you feel like yourself again, the AASM guidance is direct that routine repeat testing is not recommended for patients in this situation. There isn’t good evidence that retesting someone who’s doing well on treatment changes their outcome, and it isn’t something you should feel like you’re “falling behind” on if your provider hasn’t brought it up.
Minor comfort adjustments, like switching from a nasal mask to a full-face mask, or fine-tuning pressure within a small range, also typically don’t require a full repeat study. These can often be handled through a conversation with your provider and a review of your machine’s data.
Troubleshoot at Home vs. See a Sleep Specialist
| Situation | What Usually Helps |
| Mask leaks, dry mouth, or minor discomfort | Check mask fit, humidifier settings, and equipment condition first |
| Consistent use but symptoms returning | Talk to a sleep specialist about your machine’s data and possible re-titration |
| Significant weight change since your last study | Bring this up with your sleep specialist, even without other symptoms |
| New heart or blood pressure diagnosis | Mention this at your next sleep medicine visit |
| Switched to an oral appliance or other non-CPAP treatment | Follow-up sleep testing is recommended to confirm it’s working |
| Machine data shows elevated residual events | Needs a specialist’s review, not just a pressure guess |
What About Insurance and Medicare?
It’s a common assumption that Medicare or insurance requires a new sleep study on some kind of set schedule, every few years, for instance. That isn’t accurate. Medicare’s actual requirement is a single clinical re-evaluation with your treating physician, done between day 31 and day 91 after you start CPAP therapy, confirming your symptoms have improved and that you’re using the device consistently. Beyond that initial window, Medicare does not require a new sleep study on a routine schedule.
The one related scenario worth knowing about: if your CPAP machine itself needs to be replaced after its typical five-year usable lifetime, Medicare requires a clinical evaluation confirming you’re still using and benefiting from the device, but this does not require a new sleep study or trial period. That’s a meaningful distinction if you’ve heard otherwise, replacing an aging machine is not the same thing as needing a new titration.
Coverage specifics vary by plan, so it’s worth confirming details with your insurance provider directly, but the underlying clinical requirement isn’t a recurring testing schedule.
What Happens During a Re-Titration Study
A repeat titration follows a similar process to your original sleep study, but with a more focused goal. You’ll typically spend a night either in a sleep lab or, in some cases, using a home-based auto-adjusting device, depending on what your specialist is trying to evaluate. Sensors track your breathing, oxygen levels, and sleep patterns while your CPAP pressure is adjusted to find the setting that best controls your symptoms now, which may be different from what worked when you were first diagnosed.
Results from the study give your sleep specialist concrete data to work from rather than relying on guesswork, whether that means adjusting your existing pressure, considering a different device type like BiPAP, or exploring another treatment path entirely.
Ready to Find Out What’s Going On?
If your CPAP hasn’t felt effective lately and you’ve already ruled out the basics, mask fit, filters, humidity, hours of use, it’s worth having a sleep specialist look at what your machine’s data is actually showing and whether a re-titration sleep study could help.
At The Sleep Clinic in Rockville, MD, we work with patients through exactly this kind of reassessment, using both in-lab and home-based options depending on what your situation calls for.
📞 Call us: 301-291-5671 📍 9707 Medical Center Drive, STE 230, Rockville, MD 20850
FAQs:
Q1. Does a CPAP machine stop working over time?
Ans: The machine itself typically doesn’t “wear out” in a way that changes its pressure output, but your body’s needs can change due to weight, health conditions, or aging, which is why the same pressure setting may stop feeling effective even though the machine is functioning normally.
Q2. How do I know if it’s my mask or my pressure setting?
Ans: Start with the mask. Check for leaks, cushion wear, and fit, since these are the most common and easiest issues to fix. If symptoms persist after ruling out equipment issues, that points toward a pressure or treatment issue worth discussing with a sleep specialist.
Q3. Do I need a full overnight sleep study for a re-titration?
Ans: Not always. Depending on your situation, a re-titration might be done in a sleep lab or through a home-based auto-adjusting device. Your sleep specialist will recommend the option that fits your specific clinical situation.
Q4. Will Medicare or insurance cover a repeat sleep study?
Ans: Coverage depends on medical necessity and your specific plan, but Medicare does not require a new sleep study on a routine schedule. A re-evaluation is generally tied to documented symptoms, adherence data, or a significant health change, not a fixed timeline.
Q5. Is it normal for CPAP pressure needs to change over the years?
Ans: Yes. Weight changes, aging, new medications, and evolving health conditions can all affect how much pressure your airway needs, which is exactly why re-titration exists as an option.
Q6. What if my machine shows a high residual AHI but I feel fine?
Ans: This is genuinely unclear territory even in the clinical guidance, an elevated residual AHI without symptoms doesn’t have an obvious universal answer. It’s worth mentioning to your sleep specialist rather than assuming it’s automatically a problem or automatically nothing.
Q7. Can I just increase my CPAP pressure myself if I think it’s too low?
Ans: This isn’t something to adjust on your own. Pressure changes should be guided by your sleep specialist, ideally based on your machine’s data or a formal re-titration, since increasing pressure without proper evaluation can introduce new problems like mask leaks or discomfort without actually solving the underlying issue.
Q8. How soon after starting CPAP would I need a re-titration?
Ans: Generally, it’s reasonable to give your body a few months to adjust to a new pressure setting before considering another study, unless symptoms are severe. If problems persist beyond that adjustment period despite consistent use, that’s the point to bring it up with your provider.
