What is sleep apnea?
October 24, 2025
Sleep apnea is a disorder in which you stop and start breathing (apneas) or experience shallow breathing (hyopneas) during sleep.1 This prevents your body from getting oxygen and interrupts your natural sleep patterns. Sleep apnea is a serious medical condition that can impact your health and well-being. It’s important to know the signs of sleep apnea, if you’re at risk and how to get diagnosed and treated.
Sleep apnea definition and meaning
Sleep apnea is a medical condition that interrupts your sleep due to muscle contractions in your airway that temporarily cut off your oxygen supply. It causes you to continuously wake up to resume normal breathing throughout the night. People living with sleep apnea may stop breathing and wake up 240 times or more during a full eight hours of sleep.1 As a result, if you suffer from sleep apnea, this lack of sleep often leaves you feeling exhausted, with low energy and craving caffeine during the day.
Types of sleep apnea
Even though sleep apnea is a blanket term, there are actually a few distinct types of sleep apnea:
- Obstructive sleep apnea (OSA)
- Central sleep apnea (CSA)
- Complex sleep apnea (TESCA)
You and your doctor will work together to understand the best treatment options for you based on your sleep concerns and sleep apnea type.
Obstructive sleep apnea (OSA)
The most common type of sleep apnea, affecting almost one billion people globally2, obstructive sleep apnea (OSA) occurs when the muscles of the throat relax and narrow, restricting the amount of air going to your lungs. The brain responds by sending a signal to wake up and breathe, which can happen multiple times during the night.
Central sleep apnea (CSA)3
A less common type of sleep apnea, central sleep apnea (CSA), occurs when the brain fails to send a signal to the muscles that control your breathing, resulting in pauses in breathing during sleep.
Complex sleep apnea3
Sometimes referred to as treatment-emergent central sleep apnea (TECSA), it is a form of central sleep apnea that emerges during the early stages of treatment for obstructive sleep apnea. In most cases, TECSA resolves on its own without the need for further intervention.
Symptoms of sleep apnea1
Everyone has a bad night’s sleep now and then. But, as a chronic condition, sleep apnea makes the effects of regularly disrupted sleep even more intense. From work to relationships to your overall motivation, untreated sleep apnea can take a toll on many aspects of your life.
Snoring
Snoring is one of the most common symptoms of sleep apnea. It occurs when your neck muscles relax and your throat partly closes and becomes narrow, causing the vibration sound known as snoring.
Waking up gasping for air
When your breathing is restricted, your brain sends a signal to wake up to breathe. This can cause a sudden and startling gasp for air.
Difficulty concentrating during the day
A lack of restful sleep interrupts your body’s natural circadian rhythm and can impair cognitive function. Daily activities that require attention, critical thinking or memory can be impacted by sleep apnea.
Consistent daytime tiredness
Sleep apnea can make you feel like you’re sleepwalking through life. Sleep is a time for our bodies to rest and repair, and missing key stages of the sleep cycle can leave you feeling drained.
Morning headaches
Periods of disrupted breathing can cause your blood oxygen levels to drop during sleep, resulting in morning headaches. While the headaches may not last for long, they may be an indicator of sleep apnea.
Difficulty staying asleep
Sleep apnea and insomnia can be a vicious cycle. You may wake up from apneas and worry about not sleeping, then struggle to sleep because you’re worried.
Waking up with a dry mouth
When your airway is blocked, it can lead to snoring or breathing with your mouth open, both of which can cause you to wake up with a dry mouth.
Irritability and mood swings
A lack of quality sleep can leave you feeling tired and irritable. This can make even the simplest tasks a struggle, which can impact your mood. There’s also a strong link between sleep apnea and mood disorders. In fact, 35% of people living with sleep apnea have symptoms of depression.4
Sleep apnea causes
Each type of sleep apnea comes with its own causes. Understanding the cause behind your sleep apnea can help you address some symptoms and get the most effective treatment for your condition. While some causes are unavoidable or genetic, you may be able to make lifestyle changes that reduce your risk.
Obstructive sleep apnea causes
Causes may include alcohol use, smoking, narcotic drug use and excess weight. Other causes can include age, gender, allergies, a narrow airway, enlarged tonsils or adenoids, a receding chin or a deviated septum.
Central sleep apnea causes
Causes can include high altitude, narcotic drug use or underlying medical conditions, such as heart failure or stroke.
Complex sleep apnea causes
While complex sleep apnea, otherwise known as treatment-emergent sleep apnea is not fully understood, a small percentage of patients develop it during treatment for obstructive sleep apnea.
Sleep apnea risk factors
While it’s true that people who snore, are older, have other medical conditions and are male may be at risk of sleep apnea, they’re not the only ones. Sleep apnea can affect people of all ages, races, genders, shapes and sizes. However, there are some general risk factors to keep in mind. Knowing more about these risk factors can help you have a conversation with your doctor about sleep apnea.
Obesity
Weight can be a common sleep apnea factor. People with excess weight or obesity tend to have fat deposits in their upper respiratory tract, narrowing the airway and causing obstructed breathing.
Gender
Men are more susceptible to sleep apnea than women. The prevalence of moderate-to-severe sleep disordered breathing is 23.4% in women and 49.7% in men,5 although women become more susceptible during pregnancy and after menopause.
Age
Aging naturally impairs the brain’s ability to control the throat muscles. People over 40 are more likely to develop OSA.
Neck size
Excess weight around your neck can narrow your airway when you lie down. A neck circumference of 17 or more inches in men and 16 or more inches in women can increase the likelihood of developing sleep apnea.
Smoking and alcohol use
Smoking affects your respiratory system and can cause inflammation and narrowing in your upper airway. Alcohol can slow your breathing and over-relax your throat muscles. Both can cause or make sleep apnea symptoms worse.
Long-term effects of sleep apnea
While the short-term symptoms of sleep apnea can be frustrating, its long-term effects can be potentially life-threatening. If left untreated, sleep apnea can lead to heart disease, stroke, high blood pressure and cognitive decline. Because sleep apnea interrupts a much-needed good night’s rest, it can impact organ function, mood and daily energy levels. Early detection, diagnosis and treatment is the best way to potentially avoid these long-term risks.2
How is sleep apnea diagnosed?
Your doctor can make a recommendation or referral to a sleep specialist based on your current symptoms. It’s important to discuss your symptoms with your doctor early, so they can determine if a sleep test is the right step to take next. There are two types of sleep tests your doctor can recommend:
- Home sleep test (HST): Your doctor may recommend a home sleep test if you’re showing symptoms of a sleep disorder and have not been diagnosed with any other chronic medical conditions. HSTs can be conveniently completed from the comfort of your own bed, reducing the amount of time you have to wait to get tested.6
- In-lab polysomnography sleep study (PSG): Your doctor may recommend a PSG if you have a more complex medical history and may benefit from comprehensive sleep monitoring. PSGs are usually conducted overnight in a sleep lab, where a trained lab technician can monitor your sleep.6
The road to diagnosing sleep apnea has a few common steps:
1. Initial doctor visit:
Make an appointment with your doctor to discuss your current symptoms and how they relate to typical risk factors and causes of sleep apnea. Your doctor will be able to measure your symptoms against your broader health history to determine if you should see a sleep specialist.
2. Sleep specialist visit:
A referral to a medical sleep specialist will include a more in-depth evaluation of your sleep patterns, current symptoms and overall past health record. The sleep specialist will help determine if you need further evaluation.
3. Sleep apnea test:
An official sleep apnea test can either occur at home or at a sleep study center. This test is an overnight evaluation that involves monitoring your breathing and other bodily functions–such as your blood oxygen levels and heart rate– while you sleep.
4. Sleep apnea test results review:
After completing a sleep apnea test, your test results will include measurements of breathing patterns, arm and leg movements, blood oxygen levels, heart rate and overall airflow. A specific measurement linked directly to sleep apnea is the apnea-hypopnea index (AHI), which will also be assessed during the overnight sleep apnea test. Your AHI measures the severity of sleep apnea based on the number of times your breathing was excessively shallow (hypopneas) or when it stopped altogether (apnea) during each hour of sleep.
- AHI Ranges
- < 5 Normal
- 5 – 14 Mild sleep apnea
- 15 – 29 Moderate sleep apnea
- 30+ Severe sleep apnea
- Link to Sleep Apnea Diagnosis and Testing Page
Sleep apnea treatment options
If you are officially diagnosed with sleep apnea, your healthcare provider will discuss treatment options for the specific type of sleep apnea you have. Treatment options can include a mixture of lifestyle changes, sleep devices and medications, or even surgical treatments. It may take a little time to get used to these changes in your routine, but ultimately, your sleep apnea treatment plan should have a positive impact on your sleep and improve your quality of life.
CPAP therapy
Continuous positive airway pressure (CPAP) therapy is highly effective and is the most used and understood method for treating sleep apnea.7 It involves a mask that fits over your nose and/or mouth and connects to a machine that pushes air through the mask. This flow of air is continuously delivered to your airway and helps prevent the stops and pauses in overnight breathing that sleep apnea can cause. In short, CPAP helps you breathe during the night, so you wake up feeling refreshed and well-rested.
Other airway pressure devices
Some people may have trouble getting used to CPAP. In those cases, auto-adjusting positive airway pressure (APAP) therapy allows the level of delivered air to adjust based on the person’s needs. It only delivers the amount of pressure needed at any given moment. Bilevel PAP devices are a variation of CPAP that deliver different pressure levels during inhalation and exhalation.
Lifestyle changes
Whether or not you have sleep apnea, lifestyle changes may benefit you. Your doctor may recommend you lose weight, cut down on alcohol or quit smoking to help improve your sleep apnea symptoms.
Oral appliance therapy
CPAP therapy is the gold standard for treating mild to moderate sleep apnea, although doctors may prescribe oral appliance therapy as an alternative option. An oral appliance, or a mandibular repositioning device (MRD), holds your lower jaw in a forward position while you sleep. A part of the device expands the space behind the tongue and puts tension on the walls of the throat to help keep the airway open and reduce palate vibration.
Medication changes
Your doctor may review your medications to determine if they’re contributing to your sleep apnea symptoms. Medications such as antihistamines, opiates and benzodiazepines for anxiety can exacerbate sleep apnea symptoms by causing the airway to relax and narrow.
Nasal decongestants
If you’re suffering from allergies or chronic nasal congestion, your doctor might prescribe nasal decongestants to reduce the swelling of the blood vessels in your nose and open your airway. This is referred to as hypoglossal nerve stimulation (HGNS) or upper airway stimulation (UAS). HGNS (or UAS) is for people with moderate to severe sleep apnea who have failed on CPAP and/or oral appliance therapy.
Surgery
While surgery isn’t generally a first line of defense against sleep apnea, some surgical treatments are available. Uvulopalatopharyngoplasty (UPPP) is the most common surgery performed for OSA in the U.S. In this procedure, surgeons remove extra tissue in the throat to open the upper airway. Other less common surgical options include nasal surgery to fix a crooked or deviated septum, jaw surgery to change the position of the jaw, surgery to remove the tonsils or adenoids or somnoplasty, which uses radiofrequency to shrink the tissue in the upper airway.
Sleep apnea tips: What to do if diagnosed with sleep apnea
If you or a loved one has sleep apnea, there are things you can do to reduce symptoms and improve your quality of life. As always, consult your doctor before starting new therapies, diets or exercise programs.
Talk with your doctor
Communicate regularly with your doctor about any concerns or challenges you may be facing with the proposed treatment.
Use your CPAP consistently
CPAP can take some getting used to, but the more consistent you are with your therapy, the more likely you are to reap the health benefits.
Maintain a healthy weight
Managing your weight can help take pressure off your airway, helping you sleep more comfortably and improving your sleep apnea symptoms.
Reduce alcohol intake
Alcohol can exacerbate sleep apnea symptoms. Your best bet is to drink in moderation (or not at all) and avoid alcohol before bedtime.
Stop smoking
Smoking may increase inflammation and narrowing in your upper airway. Quitting is a positive step towards improving your sleep and your health.
Treat allergies
Allergies create nasal congestion and can dry out your mouth or block your airways. Talk to your doctor about the best solution for treating your allergies.
Are you or a loved one experiencing sleep issues or potential sleep apnea symptoms?
Take our free online sleep quiz and discuss the results with your doctor.
References
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- Source: “Sleep Apnea: What Is It?” Cleveland Clinic, https://my.clevelandclinic.org/health/diseases/8718-sleep-apnea.
- Source: Gurubhagavatula I, et al., “Obstructive Sleep Apnea Indicator Report”. American Academy of Sleep Medicine. 2023
- Source: Roberts, Erin Grattan, et al. “The Pathogenesis of Central and Complex Sleep Apnea.” Current Neurology and Neuroscience Reports, vol. 22, no. 7, Jul. 2022, pp. 405–12. DOI.org (Crossref), https://doi.org/10.1007/s11910-022-01199-2.
- Source: Jehan, S et al., J Sleep Med Disord. 2017
- Source: Garbarino S., et al., Behav Sleep Med. 2020
- Source: Rosenberg et al., Sleep Med. 2019
- Source: Understanding PAP | Sleep Medicine. https://sleep.hms.harvard.edu/education-training/public-education/sleep-and-health-education-program/sleep-health-education-37.
This post features a paid partnership with Remi Bader, who is a Resmed brand partner. She received compensation for sharing her personal experience with Resmed products. As with any medical device, individual results may vary.