Most people snore once in a while. But if your snoring is caused by sleep apnea, then it's a sign of a problem. Left untreated, sleep apnea can increase your risk of high blood pressure, heart attack, diabetes, and other health conditions.1-4 Sleep apnea is a serious and possibly life-threatening condition. It's important to know its symptoms and to talk to a health care professional if you think you have sleep apnea.

What is Sleep Apnea?

Sleep apnea is a sleep disorder in which a person’s breathing repeatedly stops and starts. There are three main types of sleep apnea: obstructive sleep apnea, central sleep apnea, and complex sleep apnea syndrome.

Obstructive Sleep Apnea

Obstructive sleep apnea causes the muscles in the throat to relax repeatedly during sleep, which blocks the airway and interrupts breathing. When the muscles relax, the airway narrows or even closes so the person can't get enough air. This results in a lower level of oxygen and an increased level of carbon dioxide in the blood. The brain senses the inability to breathe and briefly rouses the person from sleep to reopen their airway. This can cause snorting, choking, or gasping. Usually, this awakening is so brief that a person doesn't remember it.1,4 This pattern can repeat itself 5-30 times or more an hour, all night long – impairing the ability to reach the deep, restful phases of sleep.1,4

Central Sleep Apnea

Central sleep apnea is less common than obstructive sleep apnea. It occurs when the brain doesn't send signals to the breathing muscles – which means the person makes no effort to breathe for a short period. Central sleep apnea might cause the person to awaken during sleep with shortness of breath or have a difficult time getting to sleep or staying asleep.3

Complex Sleep Apnea Syndrome

Complex sleep apnea syndrome is when a person has both obstructive sleep apnea and central sleep apnea.1,3

Common Symptoms of Sleep Apnea

Snoring and gasping or choking during sleep are typically the most well-known traits of sleep apnea. Common signs and symptoms of the condition include: 1-4

  1. Loud snoring
  2. Episodes in which breathing stops during sleep
  3. Gasping for air during sleep
  4. Awakening with a dry mouth
  5. Difficulty staying asleep (insomnia)
  6. Excessive daytime sleepiness (hypersomnia)

Less familiar Signs of Sleep Apnea

Not everyone who snores has sleep apnea. And not everyone who has sleep apnea snores. Other signs of sleep apnea that might surprise you include:

  1. You seem to always have a headache in the morning. You wake up most mornings with a headache, which can last for several hours. The pain is usually located toward the front of your head and on both sides. It might feel as if your head is being squeezed.1,4
  2. You can't concentrate during the day. You have trouble concentrating because obstructive sleep apnea makes it hard to get enough restorative sleep. Keep track of how often it's difficult for you to concentrate at work, at school, or on a project. You might also find yourself falling asleep or nodding off while reading, watching television, or driving.1,2,4
  3. You experience mood changes, such as feeling irritable or depressed. You might frequently feel angry or annoyed, even at slight inconveniences. You might also feel generally down, depressed or sad, and frequently cry.1,4,5
  4. You constantly sweat in your sleep. Waking up to sweaty sheets and pajamas on a regular basis can be a symptom of obstructive sleep apnea.1,2,4
  5. You rarely feel in the mood for sex. Obstructive sleep apnea can decrease your libido.2,4
  6. You often wake up with a sore throat – but you aren't sick. You might wake up with a dry and/or sore throat due to repeated gasping, choking, and blocked airflow during sleep.1,2,4

Anyone Can Have Sleep Apnea

Sleep apnea can affect anyone, and it's more common than you think. One study estimated that 936 million adults, worldwide, ages 30-69 have some level of sleep apnea, ranging from mild to severe. The number of affected individuals was highest in China, followed by the United States, Brazil, and India.6

Men, older people, and individuals who are overweight or obese are more likely to develop the condition. Women who have sleep apnea more often report headache, fatigue, depression, anxiety, insomnia, and sleep disruption. Children can experience bedwetting, an increase in asthma symptoms, hyperactivity, and learning or academic performance issues.2 

Health Complications of Sleep Apnea

Health complications of sleep apnea can include:

1. High blood pressure or heart problems

Having obstructive sleep apnea increases the risk of high blood pressure (hypertension).1,2,4 Sleep apnea disrupts how the body takes in oxygen. Sudden drops in blood oxygen levels that happen during sleep apnea increase blood pressure and strain the cardiovascular system.7

Obstructive sleep apnea might also increase the risk of heart attack, stroke, and abnormal heart rhythm like atrial fibrillation.2,4,7 If a person has heart disease, multiple episodes of low blood oxygen (hypoxia or hypoxemia) can lead to sudden death from an irregular heartbeat.7

2. Increased risk of severe COVID 19 symptoms

There is now evidence that connects obstructive sleep apnea with developing severe COVID-19 symptoms. One study of a Chicago area health system concluded that patients with obstructive sleep apnea were eight times more likely to be infected with COVID-19. The condition was associated with an increased risk of hospitalization and twice the risk of respiratory failure.8 Another study conducted at a Finnish hospital found that 29 percent of patients admitted to the hospital for COVID-19 had obstructive sleep apnea, compared to only 3-percent prevalence of obstructive sleep apnea among general, non-COVID admisssions.9

3. Type 2 diabetes

Sleep apnea increases the risk of developing insulin resistance and type 2 diabetes.1,2,4

4. Metabolic syndrome

This disorder, which includes high blood pressure, abnormal cholesterol levels, high blood sugar, and an increased waist circumference, is linked to obstructive sleep apnea. 1,4,10

5. Complications with medications and surgery

Obstructive sleep apnea is also a concern with certain medications and general anesthesia. An individual with sleep apnea might be more likely to have complications during major surgery because they are prone to breathing problems, especially when sedated and lying on their back.1

Before you have surgery, tell your doctor if you have sleep apnea and how it's being treated.

6. Liver problems

Individuals with sleep apnea are more likely to have abnormal results on liver function tests, and their livers are more likely to show signs of scarring (nonalcoholic fatty liver disease).1

The Connection between Alzheimer's Disease and Sleep Apnea

Studies have shown that poor sleep patterns, like difficulty falling asleep or staying asleep, are associated with a higher risk of Alzheimer's disease.11

There is also research showing a link between people with excessive daytime sleepiness – a primary symptom of sleep apnea – and Alzheimer's disease. Specifically, people with excessive daytime sleepiness had higher levels of amyloid and tau proteins, the proteins that are indicators of Alzheimer's disease.11-13

It's important to note that just because you have obstructive sleep apnea doesn't mean you'll develop Alzheimer's disease. The exact cause of Alzheimer's isn't known. Scientists think that for most people, Alzheimer's is caused by a combination of lifestyle, environmental factors, and genetics.11

Obstructive sleep apnea is a serious medical condition. Check with your health care practitioner if you experience its symptoms on a regular basis or if your partner routinely complains about your loud snoring.

If you have obstructive sleep apnea and are prescribed a therapy like a continuous positive airway pressure (CPAP) device or an oral appliance, then you should wear it every time you sleep. By staying committed to your treatment plan, you can reduce the symptoms of obstructive sleep apnea and potentially reduce your risk of developing life-threatening health conditions.1,5

References

  1. Wellman A, Redline S. Sleep apnea. In: Harrison's Principles of Internal Medicine. 20th ed. McGraw-Hill; 2018. https://accessmedicine.mhmedical.com. [Accessed Jan. 4, 2021]
  2. National Heart, Lung, and Blood Institute. Sleep apnea. http://www.nhlbi.nih.gov/health/health-topics/topics/sleepapnea/. [Accessed Jan. 25, 2021]
  3. Badr M. Central sleep apnea: Risk factors, clinical presentation, and diagnosis. https://www.uptodate.com/contents/search. [Accessed Jan. 4, 2021]
  4. Kline L. Clinical presentation and diagnosis of obstructive sleep apnea in adults. https://www.uptodate.com/contents/search. [Accessed Jan. 4, 2021]
  5. Mayo Clinic. Depression. https://www.mayoclinic.org/diseases-conditions/depression/symptoms-causes/syc-20356007. [Accessed Jan. 4, 2021]
  6. Benjafield A, Ayas N, Eastwood P, et al. Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis. Lancet Respir Med 2019;7(8):687-698. 
  7. Selim B, Koo B, Qin L, et al. The association of nocturnal cardiac arrhythmias and sleep-disordered breathing: The DREAM study. J Clin Sleep Med 2016;12(6):829-837.
  8. Maas M, Kim M, Malkani R, et al. Obstructive sleep apnea and risk of COVID-19 infection, hospitalization and respiratory failure. Sleep Breath 2020 Sep 29:1-3. 
  9. Feuth T, Saaresranta T, Karlsson A, et al. Is sleep apnea a risk factor for Covid-19? Findings from a retrospective cohort study. Sleep Med Dis Int J 2020;4(3):61-65.
  10. Castaneda A, Jauregui-Maldonado E, Ratnani I, et al. Correlation between metabolic syndrome and sleep apnea. World J Diabetes 2018;9(4):66-71. 
  11. Mayo Clinic. Alzheimer's disease. https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/symptoms-causes/syc-20350447. [Accessed Jan 6, 2021]
  12. Carvalho D, St Louis E, Knopman D, et al. Association of excessive daytime sleepiness with longitudinal β-amyloid accumulation in elderly persons without dementia. JAMA Neurol 2018;75(6):672-680.  
  13. Baril A, Carrier J, Lafrenière A, et al. Biomarkers of dementia in obstructive sleep apnea. Sleep Med Rev 2018;42:139-148.