Sleep Apnea vs Insomnia: Why You Might Have Both

ACT I - A STORY YOU MIGHT RECOGNIZE

It's 2:47 a.m.

Sarah has been staring at the ceiling for the better part of an hour. Her husband is asleep beside her—snoring, actually—which is exactly the kind of irony that feels personal at three in the morning. She's exhausted. Deeply, bone-achingly exhausted. But sleep won't come.

She has tried everything. The app on her phone. The guided meditations. The magnesium supplements from the wellness influencer she follows. She cut out coffee after noon. She bought blackout curtains that cost more than her first car payment. Nothing works.

Her doctor told her she had insomnia. She believed him. She'd always been a "light sleeper," after all—wired that way, she assumed, the same way some people are morning people and some people aren't. She started a low-dose sleep medication. It helped, a little, for a while. Then it didn't. Then it made things worse.

What Sarah doesn't know—what nobody has ever told her—is that she doesn't just have insomnia. She has something else entirely. And the two conditions are feeding each other in the dark, every single night, in ways that no meditation app was ever going to fix.

Sarah's story is not unusual. In fact, it's so common there's a clinical name for it: COMISA—Comorbid Insomnia and Sleep Apnea. And if you're reading this article at an hour that feels unreasonable, there's a meaningful chance you're living it too.

ACT II - TWO CONDITIONS, ONE VERY CONFUSED PATIENT

Sleep Apnea and Insomnia: Why People Confuse Them

Before we go further, let's set the scene for both of these conditions—because understanding what they each are is the first step to understanding why they overlap so often.

If you're new to sleep apnea specifically, our guide What Is Sleep Apnea? Symptoms, Causes, and When to Get Tested covers the full picture. But here's the essential distinction between the two:

On paper, they look like completely different problems. And they are mechanistically. But here's what makes this story complicated:

ACT III - COMISA: WHEN BOTH MOVE IN TOGETHER

What Is COMISA? The Condition Nobody Warned You About

Here's the medical reality that surprises most patients: roughly 30–50% of people with obstructive sleep apnea also meet clinical criteria for insomnia. And approximately 30% of people diagnosed with insomnia have unrecognized sleep apnea.

This overlap—Comorbid Insomnia and Sleep Apnea, or COMISA—is not a fringe condition. It's one of the most prevalent sleep disorder presentations in clinical practice. And for a long time, it was also one of the most mismanaged.

Why Do Sleep Apnea and Insomnia Co-Occur So Often?

This is where the science gets genuinely fascinating. The two conditions interact through several well-documented mechanisms:

• Sleep apnea causes nocturnal awakenings. Each time the brain restarts breathing, there's a micro-arousal. Repeated night after night, these arousals condition the brain to become hypervigilant during sleep—the neurological hallmark of insomnia.
• Insomnia creates the perfect conditions for apnea. People with insomnia often sleep more lightly and spend less time in deep NREM and REM sleep—the stages where breathing is most regulated and stable. Lighter sleep makes airway collapse more likely.
• Stress and anxiety drive both simultaneously. Elevated cortisol promotes wakefulness and hyperarousal (insomnia) while also contributing to the inflammatory processes that worsen airway obstruction (sleep apnea).
• CPAP discomfort can trigger or worsen insomnia. For patients who receive a sleep apnea diagnosis and begin CPAP therapy, the adjustment period—wearing a mask, hearing the machine, feeling the air pressure—can generate the exact hyperarousal response that characterizes insomnia.

The COMISA Symptom Map

Visually, think of it this way:

The COMISA overlap zone (center) contains the symptoms shared by both conditions—which is why diagnosis is frequently missed or delayed.

ACT IV - THE RESEARCH THAT CHANGES EVERYTHING

The Study That Turned Sleep Medicine Upside Down

For years, clinicians assumed the following: treat the sleep apnea first, and insomnia would improve. The breathing problem was the root cause. The insomnia was a side effect. Fix the airway; fix the sleep.

The research said something different—and far more unsettling.

This was a seismic finding. It meant that a patient could have a severe AHI score—40 or 50 apnea events per hour—but if their insomnia was well-managed, they might function better than a patient with mild apnea and severe insomnia.

It also meant something critically important for treatment: giving someone a CPAP machine and ignoring the insomnia was likely to produce poor outcomes—even if the CPAP was working perfectly.

And that's exactly what had been happening to patients like Sarah for years.

Why Treating Only One Condition Usually Fails

When COMISA is misidentified as one condition or the other, the treatment consequences are predictable and discouraging:

• CPAP prescribed for sleep apnea, insomnia ignored: Patient can't tolerate CPAP due to arousal and anxiety; abandons therapy within weeks; apnea continues untreated. This is the most common failure pattern in sleep apnea management.
• Sleep medication prescribed for insomnia, apnea missed: Sedatives relax throat muscles and worsen airway collapse; oxygen levels drop further; morning exhaustion increases; patient assumes the medication isn't working and escalates dosage.
• CBT-I initiated without apnea diagnosis: Therapy improves sleep initiation but patient still wakes fragmented from apnea events; partial improvement leads to frustration and disengagement from treatment.

ACT V - THE SYMPTOMS THAT FOOL EVERYONE

Symptoms Patients Confuse Between Sleep Apnea and Insomnia

Part of what makes COMISA so hard to catch is that both conditions produce symptoms that are genuinely indistinguishable without clinical testing. Here are the most commonly confused presentations:

ACT VI - THE RIGHT TREATMENT WHEN BOTH ARE PRESENT

How COMISA Is Treated: A Coordinated Approach

This is the part of the story where things actually get hopeful. Because COMISA is highly treatable when both conditions are identified and addressed together. The key word is "together." Sequential treatment—fixing one, then the other—consistently underperforms integrated care.

CBT-I: Why It's the Starting Point for COMISA

Cognitive Behavioral Therapy for Insomnia is the most evidence-based treatment for chronic insomnia—and in the context of COMISA, research shows that CBT-I initiated before CPAP therapy significantly improves CPAP adherence. This makes intuitive sense: if you enter CPAP therapy with a brain trained for hyperarousal, the mask, the pressure, the unfamiliar sounds will almost certainly trigger that arousal response. CBT-I retrains the brain first.

CBT-I typically involves 6–8 structured sessions—now widely available via telehealth—covering sleep restriction, stimulus control, cognitive restructuring (challenging anxious beliefs about sleep), and relaxation techniques.

A Note on Sleep Medication and COMISA

This is a critical point for anyone who has been taking sedative-hypnotics (benzodiazepines, Z-drugs like zolpidem) for insomnia: these medications can significantly worsen obstructive sleep apnea. They relax throat musculature, reduce arousal responses (meaning the brain is slower to restart breathing after an apnea event), and may suppress the very signals that normally protect the airway.

If you're on sleep medication and haven't been evaluated for sleep apnea, that evaluation is urgent. Not because the medication will necessarily need to stop—but because the treatment plan needs to account for the full picture.

EPILOGUE - SARAH'S STORY, CONTINUED

Sarah finally went to see a sleep specialist—not because she figured it all out, but because a friend mentioned an article she'd read. The consultation was thirty minutes over a video call. Two days later, a small device arrived in the mail.

The results showed moderate obstructive sleep apnea—22 events per hour. She also scored highly on the Insomnia Severity Index. The sleep physician explained, quietly and without judgment, that she had COMISA. That neither condition had caused the other, exactly. That they'd been amplifying each other for years. That there was a clear path forward.

She started CBT-I. Four sessions in, she was sleeping through the night for the first time in three years. Then she started CPAP—slowly, with a desensitization protocol that felt almost too gentle. She woke up on a Tuesday morning, before her alarm, feeling like herself.

That feeling of waking up and not immediately dreading the day was something she'd forgotten was possible. It turned out she hadn't been a light sleeper her whole life. She'd just been undiagnosed.

Frequently Asked Questions

You Don't Have to Keep Choosing the Wrong Answer

If Sarah's story felt familiar—if you've been treating "insomnia" that never quite gets better, or sleeping with a CPAP that doesn't seem to help the way it should—there's a reason. The two conditions are often two parts of the same problem. And the right treatment addresses both.

At Texas Sleep Medicine, our board-certified sleep physicians are experienced in evaluating and treating complex presentations like COMISA. We don't just test for one thing and call it done. We look at the whole picture—and we build a treatment plan that actually matches your specific sleep physiology.

Start with a consultation or explore whether an at-home sleep test is the right first step. Either way, the path forward begins with an accurate picture of what's actually happening when the lights go out.