Does Living in Denver Make Sleep Apnea Worse?
The short answer is yes.
Living at altitude can make sleep apnea worse, and Denver's elevation (5,280 feet) is high enough to have a meaningful impact on sleep and breathing for some people. If you've ever wondered why your sleep study looked worse than expected, why your oxygen levels drop at night, or why your CPAP data changes when you head up to the mountains, altitude may be part of the answer.
Why Altitude Affects Breathing During Sleep
At higher elevations, the air contains less oxygen. To compensate, your body naturally breathes faster and deeper. During the day, this usually isn't a problem. During sleep, however, this extra breathing can lower carbon dioxide levels enough that the brain temporarily stops sending signals to breathe.
This can lead to pauses in breathing called central apneas which is a different mechanism than the obstructive apneas most people associate with typical sleep apnea.
As a result, altitude can:
Increase the number of breathing disturbances during sleep
Lower oxygen levels overnight
Cause periodic breathing (a waxing-and-waning breathing pattern)
Make existing sleep apnea worse
What Happens to Sleep Apnea at Altitude?
Sleep-disordered breathing tends to worsen as altitude increases. Even in healthy people without diagnosed sleep apnea, breathing disturbances can increase after traveling to moderate altitude. For people who already have sleep apnea, the effect can be considerably more dramatic with more breathing events per hour, more central apneas, lower overnight oxygen levels, and worse overall sleep quality.
Denver's elevation is high enough to matter, though the degree varies by person. For many, the effect is modest. For others and particularly men, older adults, people with established sleep apnea, and those with underlying heart or lung conditions the impact can be significant. One of the most consistent findings across our patients is increased nighttime oxygen desaturation: even when breathing events don't increase dramatically, oxygen levels often run lower than they would at sea level.
A Closer Look: Treatment-Emergent Central Sleep Apnea
One pattern we see often in Colorado is treatment-emergent central sleep apnea (TECSA) — central apneas that appear or worsen once obstructive sleep apnea is already being treated with CPAP.
CPAP is very effective at holding the airway open and preventing obstructive events. But it doesn't address the separate problem altitude introduces: unstable breathing control caused by low oxygen and low carbon dioxide levels. So a patient can be using CPAP correctly, have their obstructive apnea well controlled, and still see their AHI rise — not because CPAP failed, but because new central events have emerged. This is more common at altitude than at sea level, and it becomes even more noticeable when patients travel to higher elevations like Winter Park, Breckenridge, Vail, Keystone, or Aspen.
Patients often describe this as their sleep apnea being "well controlled" at home in Denver, only to feel far worse after a night or two up in the mountains with more awakenings, restless sleep, morning headaches, and higher CPAP-reported AHI.
How We Monitor and Adjust Treatment
Because altitude-related breathing instability can change from night to night and especially with travel, we don't rely on a single sleep study to tell the whole story. As part of our program, we can pull real-time and remote data downloads directly from your PAP device, so we can see exactly what's happening with your therapy on any given night: how many events are occurring, what type they are (obstructive vs. central), and how your pressure and mask fit are performing.
This matters because we can often tell the difference between a mask leak, an obstructive event, and a true central apnea and respond accordingly, often without waiting for your next in-person visit. If we see a pattern of emerging central events, especially around travel to higher elevations, we can proactively adjust your plan.
Switching to ASV When Appropriate
When central apneas persist despite well-fitted, consistently used CPAP therapy, Adaptive Servo-Ventilation (ASV) is often the next step. Unlike CPAP, which delivers a constant pressure, ASV continuously adjusts its pressure support breath by breath to stabilize breathing and reduce central events. For patients whose data shows a clear central component, particularly one tied to altitude or travel, switching to ASV can meaningfully improve both the numbers and how restorative sleep actually feels.
Not everyone with altitude-related central apneas needs ASV. This is a decision we make by reviewing your actual PAP data over time, not by assumption, which is part of why ongoing data review is so valuable.
A Note on Acetazolamide
Acetazolamide is a medication that can help stabilize breathing at altitude by affecting how the body regulates carbon dioxide, and it has a legitimate role in managing altitude-related breathing instability.
That said, we generally reserve it for short-term use. For example, around a specific trip to higher elevation rather than as a long-term daily therapy. Acetazolamide can affect the body's electrolyte and acid-base balance, and using it continuously requires careful monitoring. For most patients, we'd rather address the underlying problem with PAP optimization or ASV for ongoing management, and reserve acetazolamide for situational use, such as a ski trip to Vail or Breckenridge, where it can help in the short window that matters.
Does This Mean My Sleep Study Might Look Different Depending on Where I'm Tested?
Often, yes. A person tested in Denver may show more breathing events, more central apneas, and lower oxygen levels than the same person would show if tested at sea level and the reverse can also be true. A Colorado resident tested at sea level could appear to have milder sleep apnea than they actually experience at home. This is one reason context matters so much when interpreting a sleep study, and why we take altitude into account when reviewing your results and building a treatment plan.
The Bottom Line
Altitude and sleep apnea are closely connected. Living in Denver can worsen sleep-disordered breathing compared to sea level, primarily by increasing central apneas and lowering oxygen levels during sleep and the effect becomes more pronounced when traveling to higher elevations in the mountains.
If you live in Colorado and have symptoms such as snoring, daytime fatigue, poor sleep quality, morning headaches, or unexplained low oxygen levels, a sleep evaluation may be worthwhile. And if you're already on CPAP but notice your therapy seems less effective especially around travel, it may be worth having your PAP data reviewed rather than assuming the treatment isn't working. Understanding the role altitude plays in your sleep helps ensure your diagnosis and treatment plan are tailored to where you actually live and sleep.
If you're in Colorado and want your CPAP or PAP data reviewed for signs of altitude-related central apnea, contact our clinic to learn more about our remote monitoring program.
