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What Is a CPAP Machine? Everything You Need to Know

A CPAP machine is a commonly used treatment for a sleep disorder called sleep apnea, which is when you experience periodic gaps in breathing while you’re sleeping. CPAP stands for continuous positive airway pressure, which refers to the steady, pre-set flow of air that comes from the machine. 

Sleep apnea is the most common sleep-related breathing disorder1. It’s estimated that 9 to 38 percent of the adult population has this disorder, though researchers believe that 80 to 90 percent of cases remain undiagnosed2. CPAP therapy began in the early 1980s and is considered the “gold standard” for treating sleep apnea3.

This article will help you understand more about CPAP machines, including how they work, the pros and cons of using them, and signs that you might benefit from one.

What Is a CPAP Machine?

A CPAP machine is a small device that’s connected to a mask that you wear while sleeping. Some masks cover just your nose, while full masks cover both the nose and mouth. The machine provides a continuous flow of pressurized air through a tube, and then the air enters your nose or mouth via the mask.

Shopping for a CPAP Machine? Browse our picks for the Best CPAP Machines.

Why Would Someone Wear a CPAP?

CPAP machines are used to treat sleep apnea, which is a sleep disorder in which your breathing repeatedly stops and starts throughout the night. When your body isn’t receiving enough oxygen due to these breathing gaps, it will wake you up just enough to trigger breathing again. In cases of severe sleep apnea, this can happen as much as 30 times per hour4, and you may not even remember it happening. 

Obstructive sleep apnea (OSA) is the more common form of the disorder, which happens when your throat muscles relax while you’re sleeping, narrowing the airway and blocking airflow into the lungs.4 Central sleep apnea (CSA) is less prevalent and occurs when your brain doesn’t properly tell your breathing muscles to take in air, leading you to stop breathing for short periods of time.4 

Sleep apnea can have short-term consequences like daytime fatigue, but if left untreated it can lead to more serious complications5, such as high blood pressure, heart problems, metabolic syndrome, type 2 diabetes, and issues with liver function. 

CPAP machines can also be used in the treatment of premature babies whose lungs haven’t developed properly6.

How Does CPAP Work?

When your body isn’t breathing properly during sleep, a CPAP machine can assist by providing a flow of air that’s pressurized just enough to prevent your airways from collapsing7. It does this by preventing your tongue, uvula, and soft palate8 from moving into the airway, which stabilizes breathing. The machine filters and pressurizes air drawn in from your bedroom, before sending it through the tube and mask.

Benefits of Using a CPAP Machine

  • Better sleep quality – A major benefit of CPAP is that it can improve sleep quality by preventing awakenings caused by sleep apnea. A 2022 study9 on patients with type 2 diabetes and obstructive sleep apnea found that sleep was improved in those who used CPAP devices, which can, in turn, reduce daytime fatigue. 
  • Reduced risk of health complications – A recently published study10 on thousands of patients with OSA in Catalonia showed that those who consistently used their CPAP machines had a 36 percent reduced risk of dying from cardiovascular disease, an 18 percent lower risk of being hospitalized with cardiovascular disease, and a 40 percent lower risk of dying by any cause. In patients with both type 2 diabetes and sleep apnea, CPAP intervention has been shown to both reduce and stabilize blood glucose levels11

What Are the Side Effects of Using a CPAP Machine?

It can take some time to get used to sleeping with a mask on; some reported issues include general discomfort and claustrophobia12. You may also feel disturbed by the noise of the machine. 

An ill-fitting mask might cause skin irritation and nasal dryness, and air leaks from a poorly fitted mask could lead to inadequate air pressure. Some users also complain of bloating, burping, or flatulence caused by ​​aerophagia13, which is when you inadvertently swallow too much air.

How to Improve Your CPAP Experience

  • Make sure your mask fits well – An ill-fitting mask may cause discomfort and prevent your device from delivering the correct amount of air pressure to prevent apnea. It’s important to speak to your healthcare provider about choosing the right style and size of mask for you.
  • Ease yourself into using it – Wearing a CPAP mask might feel strange at first, so try to get used to it by wearing just the mask for brief periods while watching TV or reading, and then wearing it with the machine turned on. Once you’re used to how it feels, you should wear it every time you sleep. If the pressure feels too much when you’re trying to fall asleep, try the ‘ramp’ mode14 on your machine if you have that feature, which will gradually increase the air pressure.
  • Address noise disturbances – Most modern CPAP machines are relatively quiet, but if you’re sensitive to noise, you can try placing the machine as far away from the bed as possible or wearing earplugs. You can also look at customer reviews of CPAP machines to see which ones perform best at minimizing noise.

Signs You May Need to Use a CPAP Device

  • Excessive daytime tiredness – Extreme tiredness during the day is a common symptom of sleep apnea. This is caused by the frequent nighttime awakenings that interrupt the natural sleep cycle15.
  • Loud snoring – Not everyone with sleep apnea snores, and not all snorers have sleep apnea. However, it’s a common symptom of the condition16. So if you’ve been told you snore and also experience daytime fatigue, it may be worth speaking to your doctor.
  • Gasping for air during the night – Waking up gasping for air is another symptom of sleep apnea, which happens when the body is starved of oxygen.5 However, you may not be aware of it happening, so it could be something a co-sleeper notices. 
  • Waking up in the night to pee – Nocturia is the name for waking up twice or more during the night to pee, and research shows that around 50 percent of OSA patients have this17.
  • Depression – Depression isn’t necessarily a sign of sleep apnea, but research shows that people with sleep apnea have a higher chance of experiencing depressive symptoms18.

If you notice any of these symptoms and suspect you might have sleep apnea, it’s best to consult your doctor, who can properly diagnose the condition. They may refer you to a sleep clinic to undergo an overnight sleep apnea sleep study, or home testing may be recommended, which could result in you receiving a prescription for CPAP treatment.

Frequently Asked Questions

What exactly does a CPAP do?

A CPAP machine is used in the treatment of sleep apnea, a sleep disorder characterized by periodic gaps in breathing during sleep. The CPAP delivers pressurized air through a mask to help keep your airway open so that you’re able to breathe continuously.

Is a CPAP machine just oxygen?

A CPAP machine doesn’t deliver pure oxygen; rather it filters and pressurizes regular air from the room you’re in.

Does Medicare cover CPAP machines?

If you’ve been diagnosed with sleep apnea, Medicare may cover a three-month trial19 of a CPAP machine. After this trial period, Medicare may continue to cover CPAP therapy if your doctor confirms that you meet the requirements and that it’s beneficial for you.

Typically, once your Part B deductible has been met, you must pay 20 percent of the machine rental and the cost of parts like masks and tubing, and you’ll eventually own the machine after it’s been rented for 13 consecutive months.19 However, there are strict compliance rules19 to adhere to; you must use the device for at least four hours per night, on 70 percent of nights per 30-day period.

What does CPAP stand for?

CPAP stands for continuous positive airway pressure. Put simply, this means that a steady flow of pressurized air is delivered to your airways, helping you to breathe properly. The amount of air pressure is pre-determined by your healthcare provider based on your needs.

Lisa Bowman

Lisa Bowman


About Author

Lisa is a content writer for Sleep Advisor, which combines two of her greatest passions – writing and sleeping. She can also be found writing about fitness, sustainability and vegan food.

Combination Sleeper


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