COMISA: Understanding the Overlap of Insomnia and Obstructive Sleep Apnea

For years, obstructive sleep apnea (OSA) and insomnia were treated as entirely separate sleep disorders. One involved breathing interruptions; the other involved difficulty falling or staying asleep. But research now shows that these two conditions often appear together, a combination known as COMISA, short for comorbid insomnia and sleep apnea.

Today, COMISA is recognized as one of the most common and most challenging sleep disorder combinations, affecting millions of adults worldwide. Unfortunately, it is also significantly underdiagnosed and undertreated. When these two conditions overlap, they amplify one another, leading to worse sleep, poorer daytime functioning, and an overall decline in quality of life.

In this article, we break down what COMISA is, why it happens, how it affects health, and how modern treatments can help patients finally get relief.

What Is COMISA?

COMISA stands for Comorbid Insomnia and Sleep Apnea. It describes a clinical condition where a person experiences both chronic insomnia and obstructive sleep apnea at the same time.

• Insomnia involves persistent difficulty falling asleep, staying asleep, or waking too early.
  
  

• Obstructive sleep apnea is a disorder where the airway repeatedly collapses during sleep, causing choking, gasping, or pauses in breathing.
  
  

On their own, each disorder can significantly impact sleep quality. But when they coexist, as they do in an estimated 30–50% of patients, the effects multiply. COMISA is more severe than either condition alone, often requiring a tailored treatment strategy instead of traditional single-disorder approaches.

Why Insomnia and Sleep Apnea Often Occur Together

COMISA isn’t just coincidence. There are several physiological and behavioral links between insomnia and obstructive sleep apnea that explain why so many patients have both.

1. Sleep Apnea Interrupts Sleep Architecture

People with OSA frequently wake up, sometimes dozens or even hundreds of times per night, because their airway collapses. Over time, these repeated arousals condition the brain to remain vigilant in sleep, which contributes to the development of chronic insomnia.

2. Hyperarousal Makes Sleep Apnea Worse

Insomnia is fueled by a state of hyperarousal (a revved-up nervous system). This can:

• Increase nighttime awakenings
  
  

• Reduce the depth of sleep
  
  

• Make breathing instability worse
  
  

The result? A cycle where insomnia worsens sleep apnea, and sleep apnea worsens insomnia.

3. Anxiety Around Sleep Increases Risk of COMISA

People with long-term insomnia often develop anxiety associated with bedtime, worrying about not sleeping. This anxiety heightens awareness of breathing irregularities and makes OSA-related disruptions even more distressing.

4. CPAP Intolerance Is More Common in COMISA

Patients with untreated insomnia often struggle to adapt to CPAP therapy. Difficulty falling asleep with a mask on, or waking up frequently feeling uncomfortable, contributes to lower adherence rates, further worsening symptoms of OSA.

Signs and Symptoms of COMISA

Because COMISA includes features of both obstructive sleep apnea and chronic insomnia, patients often experience a wide range of symptoms.

Common Insomnia-Related Symptoms

• Difficulty falling asleep
  
  

• Waking up during the night and struggling to return to sleep
  
  

• Waking earlier than intended
  
  

• Feeling alert or “wired” at bedtime
  
  

• Racing thoughts when trying to fall asleep
  
  

Common Obstructive Sleep Apnea Symptoms

• Loud snoring
  
  

• Choking or gasping during sleep
  
  

• Pauses in breathing
  
  

• Unrefreshing sleep
  
  

• Morning headaches
  
  

• Daytime fatigue
  
  

Symptoms That Suggest COMISA Specifically

Some red flags indicate the overlap is likely:

• Persistent insomnia even after years of suspected sleep apnea
  
  

• Sleep anxiety combined with symptoms of airway obstruction
  
  

• Trouble adjusting to CPAP or abandoning CPAP early
  
  

• Feeling exhausted even with long sleep opportunities
  
  

• Coexisting anxiety or mood disturbances
  
  

If someone has symptoms of both conditions, screening for COMISA is essential.

Why COMISA Is Often Misdiagnosed or Missed

Despite being extremely common, COMISA remains underrecognized for several reasons:

1. Patients Often Report One Disorder More Strongly

Some people focus only on their sleep anxiety or awakenings and never mention snoring. Others complain of apnea symptoms but overlook insomnia because they assume waking up often is normal.

2. Providers May Treat Only One Condition

Historically, sleep medicine treated OSA and insomnia in separate clinical “lanes.” This led to incomplete evaluations and one-sided treatment strategies.

3. Insomnia Can Mask Sleep Apnea Symptoms

People with insomnia often remain awake long enough to notice symptoms, but some never reach deeper sleep stages where OSA becomes more noticeable.

4. OSA Treatments Alone Don’t Fix COMISA

Even with CPAP, many COMISA patients still have poor sleep if the insomnia is not addressed.

Identifying COMISA early leads to dramatically better outcomes because treatment can be approached from both angles.

How COMISA Affects Health and Daily Life

COMISA is more than just “bad sleep.” When insomnia and sleep apnea coexist, the health consequences can be serious.

Amplified Daytime Fatigue

The combination of fragmented sleep from OSA and the inability to fall back asleep from insomnia results in profound exhaustion.

Increased Risk of Mental Health Conditions

Individuals with COMISA have higher rates of:

• Anxiety disorders
  
  

• Depression
  
  

• Irritability and mood swings
  
  

Because the autonomic nervous system remains hyperactive, stress levels stay elevated day and night.

Higher Cardiovascular Risk

Untreated OSA alone increases risk for:

• High blood pressure
  
  

• Arrhythmias
  
  

• Stroke
  
  

• Heart disease
  
  

When combined with insomnia, which elevates cortisol and sympathetic nervous system activity, these risks become even greater.

Impaired Cognitive Function

People with COMISA often report:

• Difficulty concentrating
  
  

• Memory lapses
  
  

• Reduced processing speed
  
  

Chronic sleep fragmentation and hyperarousal affect the brain’s ability to restore itself overnight.

How COMISA Is Diagnosed

Diagnosing COMISA involves evaluating both sides of the disorder.

1. Clinical Sleep Assessment

A sleep specialist will discuss:

• Sleep timing
  
  

• Nighttime awakenings
  
  

• Snoring or breathing issues
  
  

• Daytime symptoms
  
  

• Medical history
  
  

• Psychological factors
  
  

The goal is to identify symptoms of both insomnia and obstructive sleep apnea.

2. Sleep Study

Most patients will receive:

• A home sleep apnea test (HSAT)
  
  

• Or a full overnight in-lab polysomnogram (PSG)
  
  

This is essential to confirm or rule out obstructive sleep apnea.

3. Insomnia Evaluation

Tools such as:

• The Insomnia Severity Index (ISI)
  
  

• Behavioral assessments
  
  

• Cognitive evaluations
  
  

These help determine whether the patient has chronic insomnia and how severe it is.

A diagnosis of COMISA is made when both conditions are clinically significant and contribute to nightly sleep disruption.

Treatment Options for COMISA

Treating COMISA is not as simple as treating apnea or insomnia alone. A combined approach is essential.

1. Treating Obstructive Sleep Apnea

Common therapies include:

CPAP Therapy

The gold standard, CPAP keeps the airway open during sleep. But for COMISA patients, CPAP adherence can be challenging without addressing insomnia.

Oral Appliance Therapy

Custom dental devices can reposition the jaw to keep the airway open, particularly helpful for mild to moderate OSA.

Positional Therapy

For patients whose apnea is posture-dependent, avoiding back-sleeping may reduce symptoms.

Lifestyle Measures

Such as:

• Weight management
  
  

• Avoiding alcohol before bedtime
  
  

• Improving nasal breathing
  
  

These can support other OSA treatments.

2. Treating Insomnia Within COMISA

The most effective treatment for chronic insomnia is Cognitive Behavioral Therapy for Insomnia (CBT-I).

This includes:

• Sleep scheduling
  
  

• Cognitive reframing
  
  

• Relaxation techniques
  
  

• Stimulus control
  
  

• Sleep restriction therapy
  
  

CBT-I helps reduce hyperarousal, improve sleep efficiency, and make it easier to adapt to apnea treatments.

3. A Combined Approach: The COMISA SPA Strategy

Some treatment programs integrate a COMISA SPA (Sleep Protocol Approach), a structured method that treats insomnia and sleep apnea simultaneously.

Key components typically include:

• Tailored timing of CBT-I relative to CPAP initiation
  
  

• Education about both disorders
  
  

• Stepwise CPAP acclimatization
  
  

• Behavioral coaching
  
  

• Monitoring and adjusting therapy based on patient response
  
  

Patients following a combined approach often:

• Adhere better to CPAP therapy
  
  

• Experience fewer awakenings
  
  

• Report better overall sleep
  
  

• Reduce daytime impairment significantly
  
  

Which Should Be Treated First: Insomnia or Sleep Apnea?

There is no one-size-fits-all answer, but research shows:

If insomnia is severe, treating it first with CBT-I improves CPAP success rates.

If sleep apnea is moderate to severe, starting CPAP early is essential, but CBT-I should follow soon after.

Most specialists now recommend a coordinated, dual-focused treatment plan, rather than addressing one disorder and ignoring the other.

Living With COMISA: Long-Term Management Tips

Living with COMISA requires ongoing attention to sleep habits and health. Some strategies include:

• Maintaining consistent sleep and wake times
  
  

• Creating a calming pre-sleep routine
  
  

• Limiting caffeine and alcohol
  
  

• Keeping the bedroom cool and dark
  
  

• Using CPAP or oral appliances regularly
  
  

• Practicing stress-reduction techniques
  
  

• Attending follow-up appointments with a sleep specialist
  
  

These habits support both insomnia recovery and improved airway stability.

When to Seek Help

If you experience:

• Persistent difficulty falling or staying asleep
  
  

• Loud snoring or nighttime gasping
  
  

• Chronic exhaustion
  
  

• Trouble using CPAP
  
  

• Anxiety around sleep
  
  

• Long-term unrefreshing rest
  
  

It may be time to get evaluated for COMISA. Treating one disorder while ignoring the other often leads to frustration and lack of progress. A sleep expert can help identify the overlap and create a treatment plan that restores healthy, consistent sleep.

Final Thoughts

COMISA, the combination of chronic insomnia and obstructive sleep apnea, is far more common than most people realize. It represents a complex interaction between breathing disruptions and sleep-onset or sleep-maintenance challenges. The good news is that targeted, combined treatment approaches, including the emerging COMISA SPA strategy, can significantly improve sleep quality, daytime functioning, and long-term health.

If you suspect COMISA, don’t ignore it. Getting an accurate diagnosis and a personalized treatment plan is the most important step toward reclaiming restful, restorative sleep.