Starting CPAP: How It Works and Your First Two Weeks
Written and medically reviewed by Matthew Viereck, MD, board-certified sleep medicine physician · Reviewed November 2026 · Editorial standards
Chapters
- 0:00Starting CPAP
- 0:14Three questions
- 0:34What goes wrong in sleep apnea
- 1:03Follow the air: the machine
- 1:30The hose and the mask
- 1:47A splint made of air
- 2:06The number on your machine
- 2:26Every night, all night, naps too
- 2:50The first two weeks matter most
- 3:19The mask
- 3:53The comfort settings
- 4:26Getting used to it
- 4:51How much is enough
- 5:26Who to call
- 5:47Three things to remember
About this video
CPAP, continuous positive airway pressure, is one of the most effective treatments for obstructive sleep apnea. This video follows the air from the machine to the back of the throat, explains why CPAP has to be used every night, and covers what usually goes wrong in the first two weeks and what helps.
We follow the air through the filter, the fan, the water tank, the hose and the mask vent to the back of the throat, where the pressure holds the airway open like a splint made of air. We cover what the number on your machine means, why CPAP works only while the mask is on (naps included), what the first nights predict, choosing a mask, the comfort settings (humidity, pressure relief, the ramp and the starting pressure), how much use is enough, the four hour rule and where it comes from, and who to call for which problem.
The most important message: CPAP does not change the throat, so it works only while the mask is on. Use it every night, all night, and for naps too. A rough start is normal. If the mask or the settings are not right, change them, but do not stop.
Transcript
Show
0:00Starting CPAP
This video is for education only. It is not medical advice. Talk with your own clinician before you change your treatment. Starting CPAP: how it works, and how to get through your first two weeks.
0:14Three questions
CPAP stands for continuous positive airway pressure. It is one of the most effective treatments we have for obstructive sleep apnea. In this video we will answer three questions. How does CPAP keep the airway open? Why does it have to be every night? And what usually goes wrong in the first two weeks, and what helps?
0:34What goes wrong in sleep apnea
First, what goes wrong. The back of the throat is a soft tube, with no bone to hold it open. In sleep, the muscles around it relax. In obstructive sleep apnea, the soft palate, which is the soft back part of the roof of the mouth, and the tongue fall back and narrow or close the airway. The chest keeps trying to breathe, but little or no air gets through, until the brain wakes up for a moment and opens the throat again. This can happen many times an hour.
1:03Follow the air: the machine
Now let's follow the air. The machine pulls in ordinary room air through a filter. Nothing is added to it: no oxygen and no medicine. A small fan pushes the air out at your set pressure, and sensors inside record your hours of use, how much the mask leaks, and any breathing events. Then the air passes over a tank of water, the humidifier, which warms it and adds moisture. That is easier on the nose and mouth.
1:30The hose and the mask
The hose carries the air to the mask. On the mask is a row of small holes called the vent, and air streams out of them all night. That is on purpose. Most of each breath you breathe out leaves through the vent, so your next breath in is fresh air. Never cover or tape over the vent.
1:47A splint made of air
Then the air reaches the back of the throat, where CPAP does its work. The pressure pushes the soft palate and the tongue forward and holds the airway open, like a splint made of air. The machine does not breathe for you. You still do your own breathing. CPAP simply keeps the tube open so the air can get through.
2:06The number on your machine
The pressure is measured in centimeters of water, and for most people it falls somewhere between about five and fifteen. It is set for your own airway, either during a sleep study or by an automatic machine that adjusts itself within a range your doctor sets. If the pressure is too low, the throat narrows, and the snoring and shallow breathing come back.
2:26Every night, all night, naps too
This is the most important idea in this video. CPAP does not change your throat. It holds it open only while the mask is on. On a night without it, your airway behaves exactly the way it did before treatment. Whenever you sleep, you have sleep apnea. That is why we ask people to use CPAP every night, all night, and for naps too. Skipping it for naps is one of the most common mistakes.
2:50The first two weeks matter most
Now, the first two weeks. They tell us the most about how CPAP will go. In one study, using CPAP for more than four hours on the third night predicted good use a month later. In another, the people who would use it every night and the people who would skip nights could already be told apart by the fourth night. But a rough first night does not mean CPAP will fail. The biggest thing is consistency. Do not take a night off, even after a bad night. And if you wake up and find the mask off, put it back on.
3:19The mask
What usually goes wrong first is the mask. Most people do not stay with their first mask, and that is part of the process, not a failure. There are three main styles: nasal pillows at the nostrils, a nasal mask over the nose, and a full face mask over the nose and mouth. In the research reviewed for the American Academy of Sleep Medicine's guideline, people stuck with nasal masks better than full face masks, so a nasal style is often worth trying first. If you breathe through your mouth in sleep, a full face mask may still be best. If yours is not working, ask your equipment company for other sizes and styles.
3:53The comfort settings
Next, the settings. They matter as much as the mask, and the finer ones come down to personal preference. Some people need more humidity, and some need less. Pressure relief lowers the pressure a little each time you breathe out. Some people like it set high, and others prefer it off. The ramp starts low and builds over several minutes as you fall asleep. Some people find it essential, and others feel short of air. And a starting pressure that is too low can feel as uncomfortable as one that is too high. If something feels wrong, your doctor can adjust it. You do not have to put up with it.
4:26Getting used to it
For some people, getting used to CPAP simply takes time. One way to speed it up is to practice wearing the mask while you are awake and relaxed, for example while watching TV in the evening. A quick check in with your care team after a couple of weeks helps catch problems early, while they are easy to fix. And that kind of help works. In the same review, education, support and troubleshooting each improved how much people used CPAP.
4:51How much is enough
So how much is enough? The goal is simple: every night, all night. You may hear that four hours a night is enough. That number comes from Medicare's rule for continuing to cover the machine: at least four hours a night on seventy percent of nights, in any thirty days during the first three months. Seventy percent of thirty nights is twenty one nights. That is a coverage rule, not a health target. Your machine's report also shows your AHI, the number of times an hour your breathing stops or gets shallow. An AHI under five generally means your sleep apnea is well controlled.
5:26Who to call
Finally, who to call. Call your equipment company for mask fit, leaks, broken parts and supplies. Call your sleep clinic if you are still sleepy during the day even though you use CPAP well, if your machine shows a high AHI, or if the pressure is hard to tolerate. Mild dryness or strap marks in the first week can usually wait a few days.
5:47Three things to remember
Three things to remember. CPAP is a splint made of air, and it works only while the mask is on. Use it every night, all night, and for naps too. And a rough start is normal. If the mask or the settings are not right, change them, but do not stop. This video is not medical advice; talk with your own clinician about your treatment. The full guide, with every reference, is at bettersleepproject.com. Thank you for watching.
References
- Patil SP, Ayappa IA, Caples SM, Kimoff RJ, Patel SR, Harrod CG. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2019;15(2):301-334.
- Patil SP, Ayappa IA, Caples SM, Kimoff RJ, Patel SR, Harrod CG. Treatment of adult obstructive sleep apnea with positive airway pressure: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2019;15(2):335-343.
- Budhiraja R, Parthasarathy S, Drake CL, et al. Early CPAP use identifies subsequent adherence to CPAP therapy. Sleep. 2007;30(3):320-324.
- Weaver TE, Kribbs NB, Pack AI, et al. Night-to-night variability in CPAP use over the first three months of treatment. Sleep. 1997;20(4):278-283.
- Medicare coverage rule for PAP devices (LCD L33718), as stated by CGS
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Medical Disclaimer: This video is based on published sleep research and is provided for general education. It is not medical advice. Talk with your own clinician before starting, stopping or changing any treatment. Read full disclaimer.