Sleep apnea is a common medical condition that causes breathing interruptions, called “apnea events,” during sleep. The most common type is obstructive sleep apnea (OSA), which happens when something partially or completely blocks the upper airway during sleep. About 22 million Americans have sleep apnea.
Untreated sleep apnea can lead to serious health complications, such as stroke, heart disease, heart failure, dementia, and diabetes. It can also cause brain damage and memory loss due to a lack of oxygen to the brain during sleep. With proper treatment, sleep apnea-related brain damage is reversible.
This article will discuss how sleep apnea and brain damage are connected and the diagnosis, treatment, and prevention of sleep apnea.
Sleep Apnea and Brain Damage
Sleep apnea is associated with an increased risk of brain damage. Over time, this damage can lead to impairments in cognitive and emotional functioning, leading to problems with mood, memory, and more.
Research suggests that untreated OSA can affect the structures in the brain (such as the hippocampus and frontal cortex) that are associated with memory, mood, executive functioning (high-level thinking skills), and attention. It can also reduce the amount of gray matter—the tissue responsible for much of the brain’s ability to process information.
Researchers have identified several possible contributing factors to sleep apnea-related brain damage, including:
- Chronic sleep deprivation: Sleep apnea causes intermittent breathing interruptions throughout the night. These pauses in breathing disrupt rapid eye movement (REM) sleep cycles, which are important for learning and memory. Over time, lack of REM sleep can cause cognitive impairments (loss of brain function) such as memory loss.
- hypoxemia: The gasping and choking associated with untreated OSA cause intermittent hypoxemia (low levels of oxygen in the blood). When the brain doesn’t get enough oxygen, it can quickly lead to brain cell damage and death.
- Breakdown of the blood-brain barrier: Researchers found that untreated OSA could break down the blood-brain barrier that protects brain tissue from bacteria, infections, and chemicals. A compromised blood-brain barrier may contribute to conditions like stroke, epilepsy, meningitis, multiple sclerosis, and more.
Research on Sleep Apnea and Brain Damage
While many earlier studies focused on OSA and gray-matter volume, one 2014 study in Sleep revealed that untreated severe OSA was also associated with the breakdown of white matter in the brain. White matter is sometimes known as the “subway of the brain” due to its role in sending messages quickly between the brain and the rest of the body.
The most common signs and symptoms of sleep apnea include:
- Excessive daytime sleepiness
- Gasping or choking during the night
- Loud, frequent snoring
- Headaches or dry mouth after waking up
- Feeling tired even after a full night of sleep
- Difficulty concentrating
- Falling asleep during the day
If you suspect you might have OSA, talk to your healthcare provider about getting a referral to a sleep specialist. Sleep apnea can only be definitely diagnosed with a sleep study, also known as an overnight polysomnogram.
During a sleep study, a sleep specialist will record information about your eye and leg movements, brain activity, breathing rate, and heart rate while you sleep. This data can determine your apnea-hypopnea index (AHI), which is the number of breathing interruptions you experience in an hour. You may be diagnosed with mild, moderate, or severe sleep apnea.
The first choice of treatment for sleep apnea is positive airway pressure (PAP) therapy, which involves placing a mask over your nose or nose and mouth while you sleep. Usually, this is done with a continuous positive airway pressure (CPAP) device, which blows pressurized air into your lungs to keep your airways open during sleep.
CPAP therapy has been shown to help in the partial or complete reversal of neurocognitive impairments in people with OSA. Here are some findings about the role of CPAP devices in treating sleep apnea-related brain damage:
- One study showed that 12 months of regular CPAP use reversed white-matter damage in people with severe OSA. Participants also showed improvements in mood, quality of life, and alertness after using a CPAP machine.
- A review found that 80% of the studies reviewed reported that CPAP therapy improved executive functions such as verbal fluency or working memory. They saw partial neural recovery at long-term follow-up. However, most studies were small and didn’t have an adequate follow-up, so more research is needed.
Sleep Apnea and Alzheimer’s Disease
Without CPAP therapy, sleep apnea can potentially contribute to serious neurological conditions. Untreated sleep apnea is associated with a higher risk of developing Alzheimer’s disease. In fact, one 2020 study found that sleep apnea-related sleep damage started in the same place and spread in the same way as Alzheimer’s disease.
While anyone can get sleep apnea, there are certain risk factors for developing OSA, including:
- being male
- Being overweight
- Being post-menopausal
- Large neck circumference or small lower jaw
- Small airways
- Excessive alcohol intake
- Hypothyroidism (low thyroid function)
- Acromegaly (a condition with overproduction of growth hormone)
- Large tonsils
- A family history of sleep apnea or snoring
Here are some of the preventive measures you can take to reduce your overall risk of developing OSA:
- Losing weight
- Exercising regularly
- Reducing alcohol intake, especially before bedtime
- Not taking sedatives or tranquilizers before bedtime unless prescribed
- Sleeping in a different position, such as on your side
Sleep apnea is a common medical condition that causes intermittent pauses in breathing during sleep. Untreated sleep apnea can cause serious health complications, including brain damage and memory loss.
Untreated OSA is associated with cognitive impairments and problems with mood, memory, and alertness. Researchers believe that sleep apnea may cause brain damage due to the long-term effects of chronic sleep deprivation, as well as oxygen deficiency and the breakdown of the blood-brain barrier.
Sleep apnea-related brain damage can be partially or completely reversed in many cases with positive airway pressure (PAP) therapy, usually with a continuous positive airway pressure (CPAP) device.
A Word From Verywell
Many people do not realize they have sleep apnea. If you have excessive daytime sleepiness or your sleeping partner notices symptoms such as snoring or gasping, talk to your healthcare provider and ask about getting a sleep study. You can reduce the health risks of sleep apnea by getting treatment.
Frequently Asked Questions
Can you die from sleep apnea?
Untreated sleep apnea can lead to serious and potentially fatal health complications. These may include heart failure, heart disease, diabetes, stroke, and certain cancers. People with sleep apnea often experience excessive daytime sleepiness, which can increase their risk of being involved in fatal car crashes and other accidents.
Can sleep apnea be cured?
Sleep apnea is a chronic condition, so there is no single cure. However, sleep apnea can be effectively managed and treated. The first choice of treatment for sleep apnea is positive airway pressure (PAP) therapy, usually with a continuous positive airway pressure (CPAP) device.