What Is the Relationship Between PTSD and Sleep Apnea?

Veterans and other people with post-traumatic stress disorder (PTSD) may wonder about the potential relationship to difficulties breathing in sleep that occur with obstructive sleep apnea. What sleep problems might trauma cause? Can sleep fragmentation from untreated sleep apnea worsen PTSD symptoms?

Consider the research supporting this association, the concerning symptoms and long-term health consequences of both conditions, and how treatment of sleep apnea may improve PTSD.

What Is PTSD?

First, it is important to understand the symptoms and risk factors for post-traumatic stress disorder (PTSD). As defined by the National Institute of Mental Health (NIMH), PTSD is a condition that develops after a shocking, scary, or dangerous incident involving physical harm or the threat of physical harm.

The fight-or-flight response triggered by such a fearful event may recur months or even years later, causing ongoing symptoms. These include:

• Flashbacks
• Bad dreams (nightmares)
• Frightening thoughts
• Avoidance (of places, thoughts, or feelings) 
• Increased arousal
• Being startled easily
• Feeling tense or "on edge"
• Angry outbursts
• Difficulty sleeping (insomnia)
• Poor concentration or attention
• Memory problems
• Negative thoughts
• Distorted feelings (i.e., inappropriate guilt or blame)
• Loss of interest in enjoyable activities

PTSD commonly affects war veterans exposed to conflict, and this is an important focus of research, but it may manifest due to other traumatic circumstances, such as:

• Criminal assault
• Abuse
• Kidnapping
• Plane crashes
• Automobile crashes
• Natural disasters
• Being a refugee or migrant
• Terrorist events

According to the National Center for PTSD, about 7 or 8 out of every 100 people will experience PTSD at some point in their lives. Women are more susceptible.

PTSD may also develop due to harm affecting a friend or family member, and may occur after the sudden, unexpected death of a loved one. There are known risk factors, as well as known resilience factors that may reduce the likelihood of someone developing the disorder, despite similar exposures.

How PTSD Affects Sleep

As part of its diagnostic criteria, PTSD has two sleep-related problems noted: recurrent bad dreams (or nightmares) and difficulty sleeping characterized by insomnia. 

It is common to relive a traumatic experience through bad dreams. Research from 2002 showed that, in a general community sample, nightmares were experienced by 71% of individuals with PTSD.

In addition, difficulty falling or staying asleep in the acute aftermath of a traumatic event is a significant risk factor for the subsequent development of PTSD. Personnel with insomnia prior to trauma exposure are also more likely to develop PTSD following the exposure.

In data published from the Millennium Cohort Study in 2010, 92% of active-duty military personnel with PTSD, compared to 28% of those without PTSD, reported clinically significant insomnia. If insomnia occurs at least three nights per week and lasts for at least three months, it is deemed chronic insomnia 

Moreover, an ongoing sleep disturbance may play a critical role in the maintenance of PTSD, and sleep apnea may be one potential contribution to this persistence.

Some research suggests that the presence of more severe sleep apnea worsens PTSD symptoms concordantly. Although there is some evidence that suggests this potential relationship, not all studies have supported the association.

The Symptoms of Sleep Apnea

Obstructive sleep apnea occurs when the soft palate or tongue base partially or completely block the upper airway during sleep. This leads to a transient drop in the blood oxygen level, an increase in carbon dioxide, and the release of cortisol (stress hormone) as the brainstem triggers a brief awakening to reset normal breathing.

If this happens at least five times per hour, this is consistent with a diagnosis of sleep apnea. Not only is this stressful on the body, but it also undermines sleep quality. Sleep apnea is commonly associated with classic symptoms or signs, including:

• Snoring
• Witnessed pauses in breathing
• Gasping or choking
• Dry mouth
• Bruxism (teeth grinding or clenching)
• Palpitations
• Nocturnal heartburn
• Nocturia (frequent urination)
• Night sweats
• Frequent awakenings (insomnia)
• Morning headaches
• Excessive daytime sleepiness
• Fatigue
• Cognitive complaints (concentration, attention, or memory problems)
• Mood disorders (anxiety or depression)

Beyond these symptoms, untreated obstructive sleep apnea may have significant long-term health consequences. These include:

• Hypertension
• Diabetes
• Hyperlipidemia
• GERD
• Erectile dysfunction
• Heart arrhythmias (atrial fibrillation)
• Heart failure
• Heart attack
• Stroke
• Dementia

Someone may be unaware of many of these symptoms, and in good health, and still have unrecognized sleep apnea.

If suspected, the condition is diagnosed after a consultation with a board-certified sleep physician by undergoing either a home sleep apnea test or an in-center diagnostic polysomnogram. There has been a significant increase in demand for these services, with sleep-disordered breathing disorders affecting 22.2% of veterans in 2018 .

Connecting PTSD and Sleep Apnea

What is the relationship between obstructive sleep apnea and PTSD? Importantly, how might sleep apnea trigger increased sleep fragmentation, resulting in nightmares or insomnia, the two key sleep symptoms within the diagnostic criteria for PTSD?

Although these conditions are shared by many patients, the exact mechanism linking them is not fully understood. It is likely due to a complex interplay between sleep fragmentation and neuroendocrine pathways. As noted above, the release of cortisol associated with sleep apnea episodes may have a key role in this relationship.

It should be noted that sleep apnea is often worsened during rapid eye movement (REM) sleep. REM is when vivid dreams occur, and the muscles of the body are paralyzed so that dreams are not enacted.

This normal paralysis may also affect the airway muscles, exacerbating risk factors for sleep apnea and causing more episodes to occur. The affected person may wake gasping with associated dream recall, possibly inciting a cascade of traumatic memories.

There may be other contributing factors connecting these disorders, including:

• Disturbed sleep in combat
• Prolonged sleep deprivation
• Sleep fragmentation 
• Hyperarousal due to stressors
• Chronic stress
• Coexisting mood disorders

Further research is needed to understand this complex relationship. Fortunately, effective treatment of sleep apnea may help alleviate PTSD symptoms.

Benefits of Sleep Apnea Treatment

Obstructive sleep apnea may be effectively treated with the use of continuous positive airway pressure (CPAP) therapy. If mild to moderate in severity, the use of an oral appliance may be another acceptable alternative treatment. In some cases, weight loss, surgery, allergy treatment, or even positional therapy may be helpful.

How much does the treatment of sleep apnea benefit PTSD symptoms? There is limited research on this topic.

A small study published in 2014 included 69 veterans diagnosed with both PTSD and sleep apnea who were treated with CPAP. It found that CPAP treatment led to a decrease in daytime sleepiness, which would be expected, and a significant drop in nightmare frequency from 10.3 to 5.3 nightmares per week. 

Treatment may improve not only sleep symptoms, but overall PTSD severity as well. It would be expected that effective sleep apnea treatment would reduce awakenings, improve sleep quality, and positively affect mood. Further clinical research studies are needed to demonstrate these potential benefits.

Unfortunately, some studies suggest people affected by PTSD may have lower adherence to CPAP therapy. This may mean that people diagnosed with PTSD may require additional assistance when initiating CPAP treatment, including proper mask selection and perhaps advanced device modes (such as bilevel therapy) to optimize compliance.

At a minimum, CPAP therapy should be used at least four hours per night for 70% of the time (21 out of 30 nights) to yield benefits to health, according to research. (This is often used as the requirement for insurance coverage in the first 90 days of use.)

Ideally, the device should be used from the beginning to the end of each sleep period to optimize benefits, even with prolonged naps. This will ensure that any REM sleep period is treated, as it often occurs every 90 to 120 minutes through the night, becoming more prolonged towards morning. As a general rule, most REM sleep is concentrated in the last third of the night.

In the right circumstances, such as in the case of mild or moderate sleep apnea, alternative treatments may be pursued.

A Word From Verywell

Untreated sleep apnea may have a negative effect on sleep. Among those with PTSD, the potential sleep fragmentation may increase awakenings, nightmares, cortisol release, and other symptoms. It seems that treatment may be helpful, and it is certainly an association that should not be overlooked.

It can be challenging to determine how long a sleep disorder has been present or how it might be aggravating symptoms of other conditions. Among veterans, the ability to prove a service connection or to quality for disability benefits may be challenging.

Regardless of the incentives that may exist, optimized sleep may have significant benefits to quality of life and long-term health. Therefore, it is always advisable to seek a proper sleep evaluation and testing.