Obstructive sleep apnoea (OSA)

CPAP machines for OSA

Continuous positive airway pressure (CPAP) is the most effective treatment if you have moderate to severe OSA.

If you have mild OSA, CPAP is only recommended if your symptoms affect your quality of life or other treatment options have not worked.

CPAP is a simple machine that pumps air through a mask you wear at night. It’s designed to hold your airway open while you’re asleep. It sends air at pressure into your upper airway to stop it collapsing or narrowing. Your sleep clinic or the machine itself will set the pressure for you.

Before you leave the clinic with your CPAP, it’s really important to get clear instructions on how to fit the mask, use the machine and keep the equipment clean. It’s vital that you use the CPAP properly or the treatment won’t be effective. If you’re unsure about anything, ask the sleep clinic or call our helpline on 03000 030 555.

Getting used to CPAP

Some people wake up the first morning after CPAP and feel much better immediately, while others find it takes a few nights. Some people have vivid dreams for the first few nights, which usually stop once their body gets used to a good night’s sleep.

CPAP can feel a bit odd to start with and you may be tempted to stop using it. But people who persevere usually soon get used to it and their symptoms improve significantly – within a week of using it consistently.

When we asked people to tell us about their experience, about a third said it had taken over six months to get used to it. But almost everyone said it was the best treatment for them.

Research indicates that the longer you use it each night - up to seven hours - the more benefit you get. Try to use it every night, especially at the beginning of the night, when we tend to sleep most deeply.

If you’re having problems, ask your sleep clinic for help. You should have follow-up appointments with your sleep clinic for as long as you need.

The machine

The machine pumps air under pressure through a mask and makes a low noise that you and your partner will need to get used to.

The machine uses ordinary room air and is powered from an ordinary power supply. It should last about seven years.

The air pressure

You will not be able to adjust the air pressure once the clinic has set it. Some machines have a ramp feature that may help you to get used to the pressure. The machine starts at a lower pressure and increases to your pre-set pressure over the first few minutes.

It’s normal to feel it’s harder to breathe out. Once you’re asleep, your body will get used to this, but it may take time.

The mask

CPAP masks come in many shapes and sizes. Many sleep clinics give you a mask that fits over your nose. For it to work, you need to keep your mouth closed while sleeping.

You might need a mask that fits over your nose and mouth if you breathe through your mouth when you sleep, if you have nasal blockage or if you still snore with a nasal mask.

There are also masks that cover your whole face. At the other end of the spectrum, there are nasal pillows, which fit against your nostrils.

Your clinic should be able to help you find the best mask for you.

Getting a good seal

The mask has a soft, flexible cushion that rests against your face. Getting this cushion in the right place is important so that it is comfortable, won’t hurt you and makes a good seal with no air leaks. If the mask is too loose or too tight, the seal won’t be effective.

The tubing

The flexible tubing carries air from the machine to your mask. It may be more comfortable if you run the tubing above and behind your head. Changing the position of the machine can also help you to find a comfortable place for the tubing.


Some people find their CPAP more comfortable if it is fitted with a humidifier to moisten and warm the air from the machine. Some clinics issue humidifiers as standard with their machines. But others issue them only if you find the air from your machine uncomfortably cold and dry.

Looking after your CPAP

Your CPAP machine should come with instructions about how to use it, keeping the components clean, and washing or changing the filters. Always follow the manufacturer’s instructions.

A tip from the Humber Sleep Apnoea Support Group:

  • Wash your face before going to bed, to remove skin oils. If oil gets onto the mask cushion, it will not be as effective.
  • Avoid using skin products, such as moisturiser, before you go to bed for the same reason.

CPAP is my best friend - Kath's story

“Today I feel healthier than I did 20 years before my diagnosis”

Kath describes how CPAP treatment has made a difference to her life.

It spurred her to set up Hope2Sleep to help others use CPAP successfully too.

 I was confident my sleep test would prove I didn’t have OSA. It turned out I had moderate to severe OSA, averaging 30 apnoeas an hour.

Yes, I knew I was a snorer, and yes, I was always tired. But I put that down to being a busy music teacher and just allowed myself the odd nap when I could fit one in. I certainly wasn’t overweight.

My diagnosis was a relief. It explained why I would practically collapse with exhaustion every now and then. More importantly, I was told I could enjoy a much better quality of life with CPAP treatment.

I was excited the day I brought my CPAP machine home. I’d heard the stories of overnight cures. Well that didn’t happen. The truth is that most people have to persevere to get the comfortable night’s sleep we deserve.

I was determined to make it work. Today I feel healthier than I did in the 20 years before my diagnosis and CPAP has become my best friend.”

If you're having problems with your CPAP machine, read our advice for solutions.

Next: Surgery for OSA >

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Last medically reviewed: May 2016. Due for review: May 2019

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.