In short
- A 2019 meta-analysis of 37 studies found that 38% of people with obstructive sleep apnea also had insomnia.
- The same analysis found that 29% of people with insomnia had at least moderate sleep apnea, with an AHI of 15 or more.
- Most research suggests insomnia symptoms make people less likely to accept and keep using CPAP, according to a 2019 review.
- In a randomized trial of 145 people with both conditions, four sessions of CBT-I before CPAP led to 61 more minutes of CPAP use a night on average.
- In Sleep Heart Health Study data, having both insomnia and sleep apnea was linked with a 47% higher risk of death over 15 years than having neither.
- The American College of Physicians recommends CBT-I as the first treatment for all adults with chronic insomnia disorder.
Sleep apnea and insomnia are different conditions, but they often happen together. Insomnia is trouble falling or staying asleep, while obstructive sleep apnea is a breathing problem during sleep. When someone has both, doctors call it COMISA, and treating both usually works better than treating either one alone.
What is the difference between sleep apnea and insomnia?
The difference between sleep apnea and insomnia is the cause of the broken sleep. Insomnia is frequent, long-lasting difficulty falling asleep, staying asleep or waking too early, with daytime effects. Obstructive sleep apnea is repeated collapse of the upper airway during sleep, which causes breathing pauses, oxygen dips and arousals.
A 2019 review on the two conditions describes insomnia as a self-perpetuating disorder that involves heightened mental and physical arousal. It estimates that 6 to 10% of people have chronic insomnia disorder. Sleep apnea, by contrast, involves a narrow or floppy airway, and the same review estimates that about 10% of the general population meets diagnostic criteria for it.
The symptoms overlap more than you might expect. The American Academy of Sleep Medicine lists insomnia among the common symptoms of obstructive sleep apnea, along with unrefreshing sleep and morning headaches. Its main warning signs for sleep apnea are snoring, choking or gasping during sleep, daytime sleepiness, excess weight and high blood pressure.
| Feature | Insomnia | Obstructive sleep apnea |
|---|---|---|
| Main problem | Trouble falling asleep, staying asleep or waking too early | Airway narrows or closes during sleep |
| How it's diagnosed | Your sleep history and daytime symptoms | A sleep study that measures breathing |
| Typical clues | Lying awake, racing thoughts, worry about sleep | Snoring, gasping or choking, pauses a partner notices |
| Daytime effects | Tiredness, low mood, poor concentration | Sleepiness, unrefreshing sleep, morning headaches |
| First-line treatment | CBT-I | Often CPAP, chosen by severity |
The practical takeaway is that waking up a lot at night doesn't tell you which problem you have. It could be insomnia, sleep apnea or both. Our article on why you wake up at 3am covers some other reasons too.
How common is it to have both?
Research: moderate (what this means)Having both insomnia and sleep apnea is common. A 2019 meta-analysis of 37 studies found that 38% of people with obstructive sleep apnea had insomnia. Looking the other way, 35% of people with insomnia had sleep apnea with an AHI of 5 or more, and 29% had an AHI of 15 or more.
The meta-analysis also broke insomnia down by type. Among people with sleep apnea, 42% had trouble staying asleep, 21% woke too early and 18% had trouble falling asleep. That pattern fits with sleep apnea interrupting sleep through the night.
Earlier estimates point the same way. A 2010 review summarized in the 2019 COMISA review found that 39 to 58% of people with obstructive sleep apnea report insomnia symptoms, and 29 to 67% of people with insomnia meet minimal criteria for sleep apnea. The exact numbers depend on how each study defined the two conditions, but every estimate is high. The term COMISA itself was coined in a 2017 review by the same research group.
If you want to understand the numbers on a sleep study report, our guide to what AHI means explains the scale.
Can sleep apnea cause insomnia, or the other way round?
Sleep apnea and insomnia may feed each other. The 2019 COMISA review describes a two-way relationship, where symptoms of each condition may make the other more likely or more severe. Breathing events can wake you, and short sleep may make the airway more likely to collapse.
On one side, breathing events cause arousals and surges in the body's stress response, which may lead to full awakenings and a feeling of lying awake for long stretches. The review notes that some studies found fewer middle-of-the-night waking complaints in people with both conditions who were able to use CPAP.
On the other side, the review cites small pilot studies in which a night of total sleep deprivation reduced upper airway muscle tone in healthy sleepers, and increased AHI and lowered oxygen levels in people with suspected or mild sleep apnea.
Even when sleep apnea starts the problem, insomnia can take on a life of its own. Worry about sleep, long stretches in bed awake and changed habits can keep it going. That's one reason treating the breathing alone doesn't always fix the insomnia.
Why does having both matter?
Having both matters because each condition can make the other harder to treat, and the combination is linked with poorer health. The 2019 review describes added impairment to sleep, daytime functioning and quality of life in COMISA compared with either condition alone, and most research suggests insomnia lowers CPAP acceptance and use.
The CPAP problem makes sense. The review points out that people who spend long periods awake wearing a pressurized mask are more likely to notice side effects, take the mask off during the night or give up on CPAP altogether. Some studies haven't found this link, but most have.
There may be longer-term health effects too. A 2022 analysis of 5,236 people in the Sleep Heart Health Study defined COMISA as insomnia plus an AHI of 15 or more. About 3% of the group had both. Compared with people who had neither condition, they had higher rates of high blood pressure and heart disease at the start, and a 47% higher risk of death from any cause over 15 years of follow-up. That's an association from an observational study, so it doesn't prove that COMISA causes these outcomes, but it's a good reason not to ignore either condition. Our article on sleep apnea and high blood pressure covers one part of that picture.
How are insomnia and sleep apnea treated together?
Insomnia and sleep apnea are treated together by combining insomnia therapy, usually CBT-I, with sleep apnea treatment such as CPAP. Randomized trials suggest this combination helps people sleep better and use CPAP more. Your sleep team decides the order and the details based on your symptoms and study results.
CBT-I is the standard starting point for insomnia. The American College of Physicians recommends it as the initial treatment for all adults with chronic insomnia disorder, a strong recommendation based on moderate-quality evidence. It's a short course of therapy that works on sleep habits, time in bed and unhelpful thoughts about sleep. Our guide to CBT for insomnia explains how it works and how to find it.
The best-known COMISA trial included 145 people with insomnia and at least moderate sleep apnea. Half had four sessions of CBT-I before starting CPAP, and half went straight to usual care. Over six months, the CBT-I group:
- used CPAP for 61 minutes longer a night on average
- were more likely to accept CPAP at the start (99% compared with 89%)
- had greater improvement in insomnia severity and in unhelpful beliefs about sleep
The two groups didn't differ in other sleep or daytime measures by six months. The authors concluded that people with sleep apnea should be checked for insomnia and considered for CBT-I before starting CPAP.
Other trials have tried giving the two treatments at the same time. The 2019 review describes a trial in 125 veterans where a five-session program combining CBT-I with CPAP support, delivered by trained sleep coaches, led to 78 more minutes of CPAP use at three months and 48 more minutes at six months than a sleep education program. A trial that relied on a self-help CBT-I book given at the same time as CPAP found no difference in CPAP use, and about a fifth of those participants said they didn't read the material.
So structured, guided CBT-I seems to be what makes the difference. The review suggests that sleep clinics could build CBT-I into the education they already give people starting CPAP.
What if you're very sleepy during the day?
If you're very sleepy during the day, tell whoever is treating your insomnia. CBT-I programs often include sleep restriction, which limits time in bed for a while; the CBT-I program in the trial above included it. Daytime sleepiness is also a key warning sign of sleep apnea, and the AASM lists trouble staying awake while driving as a symptom.
Our CBT-I guide explains why sleep restriction can feel tiring at first. Working with a trained provider means the plan can take your sleepiness into account, so mention it if you drive for work or long distances. Our article on sleep apnea and driving covers why drowsiness behind the wheel matters and how treatment helps.
When should you get checked for both?
You should ask about both conditions if you have long-term trouble sleeping along with any signs of sleep apnea. Snoring, gasping or choking at night, pauses a partner has noticed, morning headaches or heavy daytime sleepiness are all worth mentioning, even if insomnia feels like the main issue.
It works the other way too. If you've been diagnosed with sleep apnea and still lie awake at night, or find it hard to keep your CPAP mask on because you're awake for long stretches, tell your sleep team. Insomnia is treatable, and the trials above suggest that treating it can make CPAP easier to stick with.
A few things to bring to the appointment:
- how long it takes you to fall asleep and how often you wake
- whether anyone has noticed snoring, gasping or pauses in your breathing
- how sleepy you feel during the day and whether you've nodded off while driving
- any sleep aids or medicines you take
Our list of sleep apnea warning signs and our guide to home sleep apnea tests can help you prepare.
Read next
- CBT-I: the insomnia treatment sleep doctors recommend first
- Sleep apnea treatment options
- Waking up tired
Common questions
What is the difference between sleep apnea and insomnia?
Insomnia is ongoing trouble falling asleep, staying asleep or waking too early, with daytime effects. Obstructive sleep apnea is repeated narrowing or closing of the airway during sleep, which causes breathing pauses and arousals. Insomnia is diagnosed from your history, while sleep apnea needs a sleep study.
Can sleep apnea cause insomnia?
It may contribute. A 2019 review describes breathing events causing arousals that can turn into full awakenings and complaints of poor sleep. Some studies found fewer middle-of-the-night waking complaints in people who could tolerate CPAP. Insomnia can then keep going on its own, so it often needs its own treatment.
What is COMISA?
COMISA stands for comorbid insomnia and sleep apnea, meaning someone has both conditions at once. Researchers coined the term in 2017. It's common: a 2019 meta-analysis found insomnia in 38% of people with obstructive sleep apnea, and the review that named it describes greater impairment than either condition alone.
Should I treat insomnia or sleep apnea first?
That's a decision for your sleep team, but research supports treating both. In one randomized trial, people who had CBT-I before starting CPAP used CPAP for longer each night and had less insomnia. Another trial delivered CBT-I alongside CPAP and also improved CPAP use.
Can I have insomnia and sleep apnea at the same time?
Yes, and it's common. A 2010 literature review found that 39 to 58% of people with obstructive sleep apnea report insomnia symptoms, and 29 to 67% of people with insomnia meet minimal criteria for sleep apnea. If you have one, ask your doctor about the other.
Do sleeping pills help if I have sleep apnea?
Talk to your doctor before taking any sleep aid if you have, or might have, sleep apnea. The American College of Physicians recommends CBT-I as the first treatment for chronic insomnia, and says short-term medicine can be added if CBT-I alone hasn't worked, after a shared discussion of benefits, harms and costs.
Sources
- Worldwide and regional prevalence rates of co-occurrence of insomnia and insomnia symptoms with obstructive sleep apnea: a systematic review and meta-analysis
- Co-morbid insomnia and sleep apnea (COMISA): prevalence, consequences, methodological considerations, and recent randomized controlled trials
- Cognitive and behavioral therapy for insomnia increases the use of continuous positive airway pressure therapy in obstructive sleep apnea participants with comorbid insomnia: a randomized clinical trial
- Comorbid insomnia and sleep apnoea is associated with all-cause mortality
- Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians
- Is it more than a snore? Recognizing sleep apnea warning signs
About this article
- Research
- 6 published sources, listed above.
- Evidence
- Moderate. How we rate it
- Last checked
- October 14, 2026
- Funding
- Paid partner of Titan Recovery. Their ads are labeled.
- Found an error?
- Tell us. We log fixes on the corrections page.
* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.