Continuous Positive Airway Pressure (CPAP)

CPAP stands for "continuous positive airway pressure." CPAP is a treatment that delivers slightly pressurized air during the breathing cycle. This makes breathing easier for persons with obstructive sleep apnea and other respiratory problems. 

Virginia Mason's sleep medicine specialists will work with you to find a CPAP pump that is appropriate for your sleeping habits. Below are some frequently asked questions about CPAPs. For more information about starting a sleep study at Virginia Mason or regarding a CPAP pump, call the Sleep Medicine Clinic at (206) 625-7180.

CPAP Frequently Asked Questions

Download and print these CPAP FAQs.

  1. What is CPAP and how does it treat sleep apnea?
  2. Are there any other treatments for sleep apnea besides CPAP?
  3. How do you know how to set the CPAP machine?
  4. What do the numbers on a CPAP machine mean?
  5. Does my insurance company or Medicare cover a second sleep study as well as the costs of CPAP?
  6. How do I obtain a CPAP machine?
  7. Can I buy a CPAP machine from a vendor on the Internet?
  8. Are there different types of masks?
  9. Can I sleep on my side or my stomach with CPAP?
  10. How do people with claustrophobia deal with CPAP?
  11. How do I know which CPAP machine and mask are right for me?
  12. What is Auto-PAP and what is BiPAP?
  13. Do I have to wear it all night every night?
  14. What are the common side effects from CPAP?
  15. Can I use a CPAP when I have an upper respiratory infection?
  16. Are CPAP machines noisy?
  17. What happens if I don't wear if for a few nights?
  18. Do I have to take it with me when I travel?
  19. Do they allow CPAP machines to be taken through airport security?
  20. How often do I get a new mask?
  21. How often do I have to wash the equipment?
  22. Do I have to use a humidifier?
  23. How often do I come in for appointments?
  24. Do I have to bring my CPAP with me to appointments?
  25. Do I have to have any more sleep studies? 

1. What is CPAP and how does it treat sleep apnea?
CPAP stands for continuous positive airway pressure. It is a small electric pump which delivers pressurized air through a mask over your nose. CPAP prevents your airway from closing while you sleep.

2. Are there any other treatments for sleep apnea besides CPAP?
Yes. You should discuss other treatments with your physician.

3. How do you know how to set the CPAP machine?
During a second sleep study, CPAP is adjusted until your breathing is normal. Except for wearing CPAP, the second study is identical to the first one. Your physician then writes a prescription for this setting.

4. What do the numbers on a CPAP machine mean?
CPAP pressure is measured in centimeters of water. This is similar to millimeters of mercury.

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5. Does my insurance company or Medicare cover a second sleep study as well as the costs of CPAP?
Medicare and most insurance companies cover the second sleep study and CPAP, subject to your benefit coverage and deductibles. 

6. How do I obtain a CPAP machine?
Durable medical equipment (DME) vendors dispense CPAP machines. Our staff will be glad to assist you in determining which DME vendor is right for you. Virginia Mason can provide you with a CPAP machine if you desire. Medicare and most insurance companies pay for rental of CPAP machines until it is clear that it is right for you. At that point, they will purchase it for you and apply all the rental fees towards the purchase price.

7. Can I buy a CPAP machine from a vendor on the Internet?
Yes, however most insurance companies will not reimburse for a CPAP machine purchased from a vendor on the Internet. If you know what you need/want and you are paying cash, this might be your best option.

8. Are there different types of masks?
Masks come in all shapes and sizes. There is no best mask, although there are some that work better or are more durable than others. These masks should be custom fitted and changed if they are uncomfortable. Most masks cover only the nose, but mouth breathers prefer masks that cover the nose and the mouth.

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9. Can I sleep on my side or my stomach with CPAP?
Some masks work better than others for side sleeping, but no masks work well for stomach sleepers.

10. How do people with claustrophobia deal with CPAP?
There are masks that work better for claustrophobic patients. Discuss this with your physician.

11. How do I know which CPAP machine and mask are right for me?
Your physician and your DME vendo will assist you in picking a CPAP and fitting you with a mask.

12. What is Auto-PAP and what is BiPAP? 
Auto-PAP is a CPAP that has a computer in it that changes the pressure throughout the night. BiPAP is a machine that delivers a higher pressure during inspiration than expiration.

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13. Do I have to wear it all night every night?
You will get most of the benefit of CPAP if you wear it four hours or more, 75 percent of the time.

14. What are the common side effects from CPAP?
Discomfort from the mask or the sensation of difficulty exhaling against pressure are the main side effects of CPAP.  Your mask can be refitted and most patients get used to breathing against the pressure. Nasal congestion or dryness, as well as mouth dryness are other side effects that your physician can usually treat.

15. Can I use a CPAP when I have an upper respiratory infection?
Most patients find it difficult to use a CPAP machine when they have a bad cold. 

16. Are CPAP machines noisy?
Most CPAP machines are very quiet. Bed partners usually prefer the "white noise" from CPAP to the loud noise associated with snoring.

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17. What happens if I don't wear if for a few nights?
Unless you have severe heart or lung disease, there is no harm going without CPAP for a night. Many patients like the way it makes them feel so much that they would not dare go a night without using it.

18. Do I have to take it with me when I travel?
Most patients make this decision for themselves. If a CPAP machine makes you feel a lot better, you will go to great lengths to take it with you. CPAP is fairly portable and should be carried onto the plane. There are some new devices on the market that are tiny and fit in a brief case. It is not clear how reliable or durable they are.

19. Do they allow CPAP machines to be taken through airport security?
Sleep apnea and CPAP are so common that these devices are easily recognized as harmless by airport security personnel. Your physician will give you a letter of medical necessity to carry with your CPAP machine. 

20. How often do I get a new mask?
Although most insurance companies will pay for a replacement mask as often as every three months, that is usually not necessary. The replacement schedule depends on your specific mask. 

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21. How often do I have to wash the equipment?
Most patients wash the hose, humidifier chamber and mask in soap and hot water once a week. They wipe the part of the mask that touches the skin daily. The head gear should be washed periodically. You do not need to sterilize your equipment. You should not soak it in chlorine or vinegar solutions. Filters need to be changed periodically depending on your particular CPAP and the quality of air in your home.

22. Do I have to use a humidifier?
The humidifier is only for your comfort and does not affect the treatment of your apnea. The need for humidity varies depending on your local climate. The heater increases the moisture content of the air if needed. Distilled water is only necessary if you have a high mineral content in your home's water supply.

23. How often do I come in for appointments?
It is a good idea to see your physician one month after starting CPAP. Your physician will determine additional follow-up appointments. Once you are stable, yearly appointments are a good idea.

24. Do I have to bring my CPAP with me to appointments?
It is safest to always bring your machine with you so that it can be tested and adjusted. Some CPAPs come with a "smart card" that can be brought to the appointment instead of the entire machine.

25. Do I have to have any more sleep studies?
In general, we do not repeat sleep studies unless there has been a significant change in your weight, it has been more than five years since your last study or you are doing poorly with your CPAP machine.

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