What You Should Know About the Dangers of Uncontrolled Sleep Apnea

Dangers of Uncontrolled Sleep Apnea

Dangers of Uncontrolled Sleep Apnea
Adobe Stock
By
Updated on October 8, 2025
by
You already know the importance of getting enough sleep. But if you have obstructive sleep apnea, you can slumber for more than eight hours and still wake up not feeling refreshed.

Because obstructive sleep apnea causes repeated pauses in breathing, your brain wakes you up briefly to reopen your airway. This repeated pattern of sleep interruption, which can occur as many as 30 times in an hour, can limit your ability to get the deep, restful sleep you need. Sleep apnea has also been linked to a host of health problems, including an increased risk of heart attack, high blood pressure, stroke, diabetes, obesity, and even glaucoma.

Adequate sleep means quality sleep, not just quantity, says Raj Dasgupta, MD, a pulmonary critical care and sleep medicine specialist at Keck Medicine of the University of Southern California in Los Angeles. “Someone may be getting seven to eight hours of sleep but still feel tired, because they’re not going into deep sleep,” says Dr. Dasgupta. “We all need deep sleep to rejuvenate.”

Here are just some of the ways sleep apnea can be harmful to your health.

10 Ways Sleep Apnea Can Be Harmful to Your Health

Discover 10 ways that obstructive sleep apnea can be harmful to your health.
10 Ways Sleep Apnea Can Be Harmful to Your Health

Next up video playing in 10 seconds

Sleep Apnea May Harm Your Heart Health

Sleep apnea has been linked to heart conditions, such as heart attacks, heart failure, and irregular heartbeat. If you have sleep apnea, you stop breathing when you sleep, which causes your heart rate to drop. When your body wakes you up to breathe again, your heart rate accelerates and your blood pressure spikes.

Sleep apnea also reduces oxygen levels in the blood, limiting the supply that goes to vital organs, says Dasgupta. Your heart, like your other organs, needs oxygen to function properly.

This reduced oxygen also increases the levels of inflammation-causing chemicals in the blood that can damage the blood vessels and heart.

While it’s important to eat a heart-healthy diet and exercise regularly, treating sleep apnea and making sure you get enough sleep can also help reduce the risk of heart disease.

Sleep Apnea May Increase Stroke Risk (and Vice Versa)

It’s unclear whether sleep apnea or stroke comes first, but experts caution that one condition could lead to the other.

For example, research has shown that sleep apnea is prevalent among people who’ve had a stroke. As many as 70 percent of them have the sleep disorder. At the same time, sleep apnea seems to be a high risk factor for stroke.

Both sleep apnea and stroke share a number of risk factors, including diabetes, hypertension, and obesity. Sleep apnea is strongly associated with atrial fibrillation (a potentially dangerous form of irregular heartbeat), congestive heart failure, coronary artery disease, and diabetes, which are all risk factors for stroke.

Sleep Apnea May Cause Weight Gain

Not everyone who is overweight has sleep apnea, but people with obesity are more likely to be diagnosed with the sleep disorder. And if you have sleep apnea, you’re also at risk of gaining weight.

What’s behind the obesity–sleep apnea link? When you gain weight, fat can accumulate in the neck area and obstruct breathing, leading to sleep apnea.

Plus, says Dasgupta, when you don’t get enough sleep, your body doesn’t produce enough leptin, an appetite-regulating hormone that helps reduce hunger. The lower the leptin levels, the harder it is to control appetite and lose weight, he explains.

Sleep apnea may also increase your risk of excessive daytime sleepiness, which may decrease physical activity levels and lead to weight gain. Losing 10 percent of your body weight can make sleep apnea less severe.

Sleep Apnea Increases the Risk of High Blood Pressure

When you stop breathing and oxygen levels fall, your brain sends a message to increase adrenaline in the body. This causes blood vessels to constrict and the heart to pump harder in an effort to increase the amount of available oxygen to the heart and brain. But these changes also cause intermittent increases in blood pressure, raise your risk of hypertension, and place significant stress on your cardiovascular system.

If you have sleep apnea and high blood pressure, it’s important to talk to your healthcare provider to make sure the sleep condition is treated. Treatment of sleep apnea is an important part of managing hypertension.

Sleep Apnea Raises Type 2 Diabetes Risk

Having sleep apnea may interfere with the body’s ability to regulate and metabolize glucose (sugar), which can increase your risk of developing insulin resistance and type 2 diabetes. That’s because sleep apnea limits the amount of time you spend in deep sleep, which is thought to be an important process for glucose regulation in the body.

The reverse is also true: If you have diabetes, you’re more likely to have sleep apnea. According to research, as many as 80 percent of people with type 2 diabetes also have obstructive sleep apnea, and the more severe the symptoms, the higher the odds of uncontrolled glucose levels.

Sleep Apnea Increases the Risk of Metabolic Syndrome

Research shows a connection between sleep apnea and metabolic syndrome, the name for a group of risk factors that increase the risk of diabetes, heart disease, stroke, and other health problems.

According to the National Heart, Lung, and Blood Institute, if you have three of the following risk factors, you have metabolic syndrome:

  • Abnormal cholesterol levels
  • High blood pressure
  • High blood sugar
  • High fasting blood sugar (a test done after not eating anything for at least eight hours)
  • Increased waist size or excess abdominal fat

Sleep Apnea Can Affect Your Brain

It’s not just your body that sleep apnea can negatively affect, but your cognitive function, too. Sleep apnea has been associated with cognitive disorders, such as a decrease in attention and concentration, impaired motor skills, and even poor memory.

For example, one study found that people with untreated sleep apnea were more likely to have cognitive issues such as problems with attention, information processing, and memory.

Plus, sleep apnea can hurt your head — literally. Because sleep apnea limits the amount of oxygen that goes to the brain, you can wake up with a headache, says Dasgupta.

Sleep Apnea Is Linked to Depression and Anxiety

Research has shown a strong link between obstructive sleep apnea and depression, regardless of factors such as age, body mass index, and sex.

One study using data from the National Health and Nutrition Examination Survey found that adults in the United States with sleep apnea are more likely to have depressive symptoms. And the severity of sleep apnea symptoms correlates to the severity of depression.

Treating sleep apnea could help alleviate the symptoms of depression. One study, which found that depression and anxiety are prevalent in people with obstructive sleep apnea, concluded that improving symptoms of obstructive sleep apnea with continuous positive airway pressure (CPAP) therapy decreases the severity of depressive and anxiety symptoms.

The Risk of Glaucoma Is Higher If You Have Sleep Apnea

According to the American Academy of Ophthalmology, people with sleep apnea are more likely to develop glaucoma, an eye disease that can eventually cause vision loss, than people who don’t have the sleep condition.

It’s not yet fully understood how sleep apnea may cause glaucoma. But as with other health problems associated with sleep apnea, researchers hypothesize that the eye disorder could stem from decreased levels of oxygen circulating in the blood.

Can Sleep Apnea Kill You? The Link Between Sleep Apnea and Accidents

In addition to the health effects of inadequate sleep due to sleep apnea, the condition has been shown to increase the risk of accidents. One review of studies on the frequency of car accidents involving people with daytime sleepiness and/or sleep apnea found that the odds of a car accident were more than double for people with sleep apnea.

“One of the ways sleep apnea presents is as excessive daytime sleepiness,” says Dasgupta. “People may fall asleep behind the wheel or experience microsleep” — brief moments of sleep that last 1 to 30 seconds that you may not even realize are happening.

If you suspect you have sleep apnea, it’s important to be treated as soon as possible. If you’ve been diagnosed with sleep apnea but continue to experience symptoms, such as excessive daytime sleepiness, talk to your doctor about whether you should try a new treatment.

The good news is that sleep apnea can be treated, which reduces the related health risks, says Dasgupta. Some people may be reluctant to go see a doctor and have a sleep study done, assuming they’ll be hooked up to monitors and machines at a sleep center, he says. But the diagnosis process is much easier than it was in decades past.

“Today, a sleep study is not the Frankenstein’s monster, with tubes coming out, [that] you might picture,” says Dasgupta. “You can do a home sleep study in your own bed.”

The Takeaway

  • Obstructive sleep apnea causes repeated pauses in breathing during sleep, preventing deep, restorative rest and increasing the risks for serious health conditions such as heart disease, high blood pressure, stroke, diabetes, and metabolic syndrome.
  • Uncontrolled sleep apnea can contribute to anxiety, cognitive decline, depression, glaucoma, and weight gain and even raise the likelihood of accidents due to excessive daytime sleepiness.
  • Effective treatments, such as CPAP therapy, can reduce many of these risks, helping improve both sleep quality and overall health.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Obstructive Sleep Apnea. Mayo Clinic. July 14, 2023.
  2. What Is Sleep Apnea? National Heart, Lung, and Blood Institute. January 9, 2025.
  3. Yeghiazarians Y et al. Obstructive Sleep Apnea and Cardiovascular Disease: A Scientific Statement From the American Heart Association. Circulation. July 20, 2021.
  4. Suusgaard J et al. Sleepiness, Fatigue, and Obstructive Sleep Apnea in Stroke Patients. Journal of Stroke & Cerebrovascular Diseases. August 2025.
  5. Noyed D. How Weight Affects Sleep Apnea. SleepFoundation.org. July 15, 2025.
  6. The Link Between Sleep and Cardiovascular Health. National Sleep Foundation. March 5, 2025.
  7. Noyed D. Sleep and Blood Glucose Levels. SleepFoundation.org. July 16, 2025.
  8. Morrison HB et al. Obstructive Sleep Apnea and Type 2 Diabetes: A Screening Approach. The Journal for Nurse Practitioners. May 2022.
  9. Tang R et al. Evaluate the Relationship Between Obstructive Sleep Apnea and Metabolic Syndrome in Real-World Data. Nature and Science of Sleep. 2024.
  10. What Is Metabolic Syndrome? National Heart, Lung, and Blood Institute. May 18, 2022.
  11. Patel A et al. Obstructive Sleep Apnea: Cognitive Outcomes. Clinics in Geriatric Medicine. August 2021.
  12. Li M et al. Association of Sleep Apnea and Depressive Symptoms Among US Adults: A Cross-Sectional Study. BMC Public Health. March 6, 2023.
  13. Wang X et al. Burdened Breaths: The Influence of Depression on Obstructive Sleep Apnea. World Journal of Psychiatry. September 19, 2024.
  14. Velescu DR et al. CPAP Therapy on Depressive and Anxiety Symptoms in Patients with Moderate to Severe Obstructive Sleep Apnea Syndrome. Medicina. October 2022.
  15. Goyal A. Sleep Apnea and Glaucoma. American Academy of Ophthalmology. March 18, 2024.
  16. Luzzi V et al. Correlations of Obstructive Sleep Apnea Syndrome and Daytime Sleepiness With the Risk of Car Accidents in Adult Working Population: A Systematic Review and Meta-Analysis With a Gender-Based Approach. Journal of Clinical Medicine. February 2022.
Meet Our Experts
See Our Editorial PolicyMeet Our Health Expert Network
chester-wu-bio

Chester Wu, MD

Medical Reviewer
Castle Connolly Top Doctor

Chester Wu, MD, is double board-certified in psychiatry and sleep medicine. He cares for patients through his private practice in Houston, where he provides evaluations, medication management, and therapy for psychiatric and sleep medicine conditions.

After training at the Baylor College of Medicine and Stanford University School of Medicine, Dr. Wu established the first sleep medicine program within a psychiatric system in the United States while at the Menninger Clinic in Houston.

See full bio
k26

Katherine Lee

Author

Katherine Lee is a writer and editor who specializes in health, science, and parenting content. She has written for Verywell, where she covered school-age parenting, and worked as an editor at Parenting and Working Mother magazines. She has written and edited numerous articles and essays on science, parenting, and children's health and development for What to Expect, the American Association for the Advancement of Sciences, the American Psychological Association, and Newsweek, among others

See full bio
See Our Editorial PolicyMeet Our Health Expert Network