CPAP 101

Everything You Need to Know about APAP Machines

Article Summary

This article answers some the most important questions people have about APAP machines. What is an APAP machine? How much does one cost? What’s the difference between CPAP machines and APAP machines? See why an APAP machine is better than a CPAP machine, and learn how one can help you in your therapy.

What Does APAP Stand For?

As it relates to PAP therapy to treat Sleep Apnea, APAP is an acronym that stands for automatic positive airway pressure.

A photo of the AirMini Auto CPAP Machine

What is an APAP Machine?

According to the Journal of Thoracic Disease, APAP machines help people with Sleep Apnea breathe easier and sleep better by keeping your airways open through the delivery of pressurized air. The air pressure acts as a splint, which gently holds your upper throat open so you can breathe easily throughout the night, free from apnea.

An APAP machine has a low range setting that delivers air at a lower preset pressure, and a high range setting that delivers air at a higher preset pressure. The two settings allow the machine to adjust itself automatically to meet your breathing needs, even as those breathing needs change throughout the night as you move in and out of the various stages of sleep or as you change sleeping positions.

APAP is non-invasive, so it is safe and comfortable. It is also a personalized treatment, tailored just for you. An APAP machine uses algorithms, which sense minute changes in your breathing then adjusts itself to provide the best pressure setting for your needs.

Other research from the Journal of Clinical Sleep Medicine, states that typically, Sleep specialists use special PAP titration studies performed in sleep centers (or as is often the case today, at home using a Home Sleep Test) to determine the proper pressure settings for each patient. That means your APAP pressures may be different from someone else’s, depending on your needs.

CPAP machines can deliver pressures as low as 4 to 5 cmH2O (centimeters of water) and as high as 20 cmH2O. Most people benefit from a CPAP setting of around 10 cmH2O.

An APAP machine, also known as automatic CPAP, works on the same principle as a CPAP machine to alleviate Sleep Apnea but the two machines are actually different.

Woman wearing a CPAP Mask

How to Treat Sleep Apnea with an APAP Machine

According to the medical journal Systematic Reviews, scientists found that treatment with an APAP machine can help treat Sleep Apnea to restore energy levels, boost overall health and improve the quality of your life, and when compared with CPAP machines, the APAP machine increased compliance and reduced symptoms. Therapy with these PAP machines can also quiet snoring and reduce your risk of complications associated with Sleep Apnea. Let’s take a deeper dive into the problem of Sleep Apnea.

Sleep Apnea is a condition that significantly affects quality of sleep and overall quality of life.

muscles in your upper throat keep your airway open, even as you sleep. If you have Sleep Apnea, though, these muscles can relax, causing the airway to collapse. The collapse can cause either partial or complete blockage of the airway. If you are like many people with Sleep Apnea, your tongue may slide back to obstruct your airway. This is especially true when you sleep on your back, as gravity pulls your tongue backwards and causes your airway to collapse even more.

Doctors refer to this as Obstructive Sleep Apnea, or OSA, which can cause you to choke and interfere with your breathing as you sleep. In some cases, you may even experience apnea, a condition in which you stop breathing. Apneas may last for 10 seconds or even longer.

To complicate matters further, breathing patterns may change throughout the night. This means you may be more vulnerable to periods of apnea during certain times of night than at others.

The pauses in breathing associated with Sleep Apnea can cause physical health problems, such as lowered blood oxygen levels, which can lead to serious health consequences, including high blood pressure, heart disease, mood problems and memory issues. Sleep Apnea also raises your risk of drowsy driving, which increases your risk for vehicle crashes.

If you are like many people with Sleep Apnea, you were unaware that you were having breathing problems while you slept. You may have noticed feeling lethargic, slow and out of energy, though, or found yourself dozing off while in traffic or during late afternoon. A bedmate or housemate may have told you that you snore, which happens when your lungs try to pull air past your collapsed airway.

With the help of sleep specialists and sleep studies, doctors can diagnose Sleep Apnea and recommend PAP treatment.

Graphic showing pricetags with popular CPAP, APAP, and BiPAP machines

How Much is an APAP Machine?

An APAP machine can cost $450 to nearly $900, depending on the features and size. The best APAP machines features include a heated hose or heated humidifier, which help improve comfort. For the most current pricing, you can view our APAP machines category page, which shows current prices of the most popular APAPs. APAP machines also come in travel sizes, so you can sleep well while on the road.

Graphic showing a man reviewing some documents.

What is the Difference between CPAP and APAP?

A CPAP machine provides continuous air pressure throughout the night. This means a CPAP may deliver 12 cmH2O all night long, even if your breathing pauses more often at one point during the night or if you roll onto your back.

An APAP machine, by comparison, can fluctuate at pressures between the low setting and the high setting to deliver oxygen at the right pressure to fit your changing needs. The machine may stay at the low setting when you sleep on your side, for example, but switch to a higher setting when you roll onto your back so that it can do a better job of holding your airway open. As it states in the Journal of Thoracic Disease:

Instead of operating at a set pressure, APAP monitors a patient’s respiratory activity in order to provide the lowest level of PAP necessary to eliminate respiratory disturbances. Algorithms are designed to increase pressure when events are noted and to decrease pressure slowly if events have not occurred for a period of time.

Showing a man using an APAP machine

APAP vs CPAP: Which One is Right for You?

CPAP may be adequate if your breathing patterns do not change much throughout the night or with changes in position. APAP may be right for you if you have Sleep Apnea more often while sleeping on your back than when you sleep on your side or stomach, for example, or if your breathing patterns change throughout the night.

APAP machines are often better than CPAP because APAP machines can also detect subtle changes in your breathing regardless of your sleeping position and adjust the air pressure accordingly.

An APAP machine can help treat your Sleep Apnea and bring you relief from the snoring, choking and drowsiness associated with this common sleep condition. You can experience maximum results with your CPAP or APAP in as little as two weeks, according to the National Sleep Foundation.

For more useful APAP, CPAP and Sleep Apnea information, as well as details about savings on equipment, please subscribe to our newsletter.



1. “Sleep and CPAP Adherence” published by the National Sleep Foundation on its website. Accessed August 9, 2018

Donovan, Lucas M. New Developments in the Use of Positive Airway Pressure for Obstructive Sleep Apnea. Published by the Journal of Thoracic Disease, August 2015. Accessed August 9, 2018.

Berry, M.D., F.A.A.S.M., Richard B and Sriram, M.D., Peruvemba. Auto-Adjusting Positive Airway Pressure Treatment for Sleep Apnea Diagnosed by Home Sleep Testing. Published by the Journal of Clinical Sleep Medicine, December 15, 2014. Accessed August 9, 2018.

Carolyn D’Ambrosio, et al. Auto-Titrating Versus Fixed Continuous Positive Airway Pressure for the Treatment of Obstructive Sleep Apnea: a Systematic Review with Meta-analyses. Published by Systemic Reviews in 2012. Accessed August 9, 2018.


  1. I wake up with a very dry mouth after using my cpap . What would you suggest ?

    • Hi A Miller, i’m sorry that you are experiencing a problem with dry mouth. This could be occurring for multiple reasons. There are a few questions that you must consider such as, what type of mask are you using? Are you using a humidifier with your CPAP Therapy?

      If you are not currently using a humidifier with your therapy, you may want to start using one. This will add moisture with your therapy which may help ease some of the dryness that you are feeling.

      Also, if your mouth falls open during your sleep, this may be an indication that you need a full face mask if you are not already using one.

      Our customer service department will be glad to assist you in narrowing down as to where the dryness may be coming from. Please feel free to reach us at: 1-800-356-5221 for further assistance.

  2. I have obstructive sleep apnea. I use a full face mask because my jaw drops open & I use a humidifier & I STILL wake up with horrible dry mouth. What can I do. Dry mouth only occurs when using my machine.

    • Hi Gingle,
      Sorry to hear about the dry mouth issue, I know that can be frustrating. You may try increasing the humidity level on your humidifier. Are you using a heated hose? If not, but have the option to add a heated hose, you may consider adding one as this may help with the dry mouth.

      Also, have you confirmed your leak rate under your therapy data? If you have a high leak rate, this could be the cause for your dry mouth.

      If you find your mask leak rate is high, please change your mask/mask cushion, or switch to a different mask style to see if this provides you relief.

      Please feel free to reach us at: 1-800-356-5221, or you may e-mail us at:, with further questions or concerns.

      Best Wishes!

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