What is a CPAP machine? Here’s what you need to know | ResMed UK

What is a CPAP machine? Here’s what you need to know

A ResMed CPAP machine and nasal mask on a bedside table, next to a lamp, a framed photo and some flowers.

May 28th 2024

Here at ResMed we’re on the frontline of the battle to help people sleep better and feel better – and a big way we do this is with CPAP machines. However, while we’re experts on the subject, it doesn’t mean that you are! So we’re going back to basics by explaining exactly what a CPAP machine is, what it does and how it could help you or someone you love.

Why would you need a CPAP machine? ➜

What is obstructive sleep apnoea (OSA)? ➜

How to know if you have sleep apnoea ➜

What exactly does a CPAP machine do? ➜

What are the benefits of CPAP treatment? ➜

What are the side effects of using a CPAP machine? ➜

Is there only one type of CPAP machine? ➜

Help for when you’re beginning PAP machine therapy ➜

Can you travel with a CPAP machine? ➜

Looking after your CPAP device and equipment ➜

How long should I use a CPAP machine for? ➜

Why would you need a CPAP machine?

A CPAP machine is used as a treatment for obstructive sleep apnoea, so if you’re diagnosed with this condition your doctor may well prescribe CPAP therapy.

What is obstructive sleep apnoea (OSA)?

Obstructive sleep apnoea, or OSA, is a sleep disorder where the soft tissues in your nose and throat relax so much during sleep that they partially block the airwaycausing you to stop breathing for periods of 10 seconds or more (pauses known as ‘apnoeas’). When this happens you will wake up briefly to gasp for breath (although you probably won’t remember doing it!) before drifting off again. This can happen hundreds of times a night and, unsurprisingly, leave you feeling a bit rough in the morning!

How to know if you have sleep apnoea

If you’ve heard that sleep apnoea has something to do with snoring, that’s right – loud snoring is perhaps the best-known symptom of sleep apnoea, along with the gasping for air. However it’s certainly not the only sign, and symptoms can vary from person to person. Some other sleep apnoea symptoms to look out for include:

  • daytime tiredness
  • morning headaches
  • poor memory
  • low mood1
  • night sweats2
  • weight gain3
  • reduced sex drive4

Some of these symptoms affect women more than men and vice versa – for more on sleep apnoea in women, see our article on the subject.

There are also some risk factors for sleep apnoea, primarily:

  • being overweight5 or aged over 656
  • taking certain sedatives7
  • drinking alcohol in the evening8 and smoking9
  • having nasal congestion or certain physical characteristics like a large tongue10 or thick neck5

While it’s important to know the risks, it’s also worth noting that people of all shapes and sizes and from all ages and background can have sleep apnoea – including children.

So if you’re experiencing any of the above symptoms, or a combination of them, or your sleep is troubling you in any way, it’s always a good idea to investigate and speak to your doctor our free sleep assessment could help you frame your discussion.

What exactly does a CPAP machine do?

A CPAP machine does two main things, and the first leads on to the second:

1. It provides continuous positive airway pressure

CPAP stands for continuous positive airway pressure, because that’s what it provides! What does this mean in practice? A CPAP device generates a steady stream of pressurised air, which you then breath in through a mask that you wear over your nose and mouth (or just your nose, see below for more on CPAP masks) as you sleep.

2. It helps your breathing as you sleep

The point of delivering this air is that it helps keeps your airway open as you sleep so you can breath more normally with fewer pauses, or apnoeas. The result? You should have a better night’s rest and feel less tired the next day.

3. Is a CPAP device the only option for treating OSA?

A CPAP machine has been described as the ‘gold standard’ treatment for people with sleep apnoea5, but there are other options you may want to discuss with your healthcare provider, depending on the severity of your OSA. For example in mild to moderate cases, OSA is sometimes treated with a ‘mandibular advancement device’ – this is a small oral appliance, like a sports mouthguard, that you wear at night to help reduce snoring and apnoeas11.

If you are overweight or living with obesity you may be encouraged to lose weight, as this can help ease OSA symptoms12. However if you have severe OSA, weight loss alone may not be enough to reduce your apnoeas without also having CPAP therapy.

In some cases, especially where OSA is being caused by a physical blockage in the upper airway, surgery may be an option, but as with all operations this comes with risks.

What are the benefits of CPAP treatment?

The most obvious benefit of using a CPAP machine is that you should start to experience fewer apnoeas and therefore feel more refreshed after a night’s sleep. And then once you are sleeping better, the symptoms associated with a poor night’s sleep – such as poor concentration or daytime tiredness – are likely to ease.

But there are a host of other CPAP benefits that may not be so obvious – including a lower risk of cardiovascular disease and lower blood pressure13,14. People whose OSA is treated with CPAP even have a lower risk of traffic accidents than those who go untreated15!

What are the side effects of using a CPAP machine?

While we’ve seen that CPAP therapy can be hugely beneficial to your health and general quality of life, like many medical treatments it can take some time to get used to and you may experience initial teething problems. The good news is a lot of these issues can be improved or resolved thanks to features present in modern CPAP machines – and of course, it’s always a good idea to speak to your doctor or healthcare provider if you’re having problems with your device.


Special features of CPAP devices


Many CPAP machines come with a built-in humidifier chamber, or you can buy an external heated humidifier. These help warm and moisten the air that you breath in through your mask, which helps prevent a dry nose or mouth and/or a feeling of stuffiness or congestion16. You can also use heated tubing or tube wrap to warm the air. These heating functions keep water droplets (condensation) from forming inside the tubing, which could lead to an uncomfortable feeling of water on your face and/or gurgling sounds in the tube.

Mask vents

Some people find the noise or feeling of air coming out through the vents of their mask disturbs them or their bed partner. That’s why some CPAP masks have special vents that diffuse this air so it doesn’t blow into your partner’s face; meanwhile woven-mesh vents can help keep sound levels low.

As well as the potential side effects mentioned above, some people may feel apprehensive about wearing a CPAP mask while they sleep and how it might affect their relationship with their bed partner. They may also worry that it will be uncomfortable or fall off during the night. This doesn’t have to be a problem though, as these days CPAP masks are designed with these concerns in mind.


Types of CPAP mask

There are three main types of CPAP mask:

  • Full face: covers both your nose and mouth
  • Nasal: surrounds the nose or sits under it
  • Nasal pillows: fits just inside the nostril area

Finding the type that’s the best fit for you will depend on your individual needs, which you can discuss with your doctor. Again there are three main things to consider, based on personal preference:

  • If you are self-conscious or claustrophobic, or just prefer a simple option, a minimalist mask could be for you, as they are designed to be lightweight, discreet and easy to use.
  • If you toss and turn a lot in your sleep, a mask that allows you freedom to move could be the answer. This can include ‘tube-up’ designs, where the mask tubing connects at the top of the head so it’s less likely to be dislodged by a flailing limb in the night.
  • If you want the reassurance of a mask that fits securely over the nose and mouth with an effective seal, then you might like a versatile solution that offers comfort for all face shapes.

Is there only one type of CPAP machine?

While OSA is usually treated with a CPAP machine, there are different forms of positive airway pressure (PAP) device that have been designed to suit different needs and conditions.


BiPAP or bilevel machines

As the ‘bi’ part of the name may suggest (if you know your Latin!), this type of machine delivers not one but two air pressures: one for when you breath in and one for when you breath out. This bilevel PAP therapy may suit people who find the constant air pressure of a CPAP device uncomfortable or hard to exhale against.


APAP machines

An automatic positive airway pressure (APAP) machine again delivers pressurised air, but this time an algorithm tracks your breathing as you sleep and adapts the pressure automatically in response to your changing needs. Some models also feature technology that gradually increases the pressure as it senses you’re falling asleep, which can be useful if you have trouble nodding off with your CPAP device at its full pressure level.

There are also other types of specialised positive airway pressure devices known as adaptive servo-ventilation (ASV) machines*. These go even further in the way that they respond to a user’s needs, and are usually used to treat sleep-disordered breathing conditions such as central sleep apnoea (CSA) rather than OSA alone. Please note this type of therapy should only be started under the guidance of a healthcare professional.

Help for when you’re beginning PAP machine therapy

Like any new change in routine, starting to use any sort of PAP machine can be daunting, but there is plenty of help at hand – on this website for starters! There are even apps available that can connect to your device and help you see how your therapy is going. The overriding message is to take your time to get used to therapy and discuss any concerns with your healthcare provider – they may suggest some exercises to help you feel comfortable wearing your mask, for example.

Can you travel with a CPAP machine?

The short answer is yes! In fact, if you’re going to be sleeping away from home, even if only for a night or two, it’s important not to stop your therapy so you can continue feeling the benefits. Our ebook On the road with PAP therapy has lots of useful tips and advice on how to be prepared, and there are also plenty of products available that can make travelling with a CPAP machine easier – you can even get smaller devices specially designed to be portable!

Looking after your CPAP device and equipment

As you continue on your CPAP journey, don’t forget to keep your CPAP machine and related equipment in tip-top condition. Not only will a daily cleaning routine and regularly air filter replacement help keep therapy feeling fresh, dirty or worn parts can interfere with the effectiveness of your treatment. Your user guides will include cleaning and maintenance instructions, so make sure you read them!

And don’t worry – you won’t need to get a whole new CPAP machine every time you find a worn or damaged component. Your CPAP supplier or healthcare provider will be able to advise you on sourcing a replacement part.

How long should I use a CPAP machine for?

Finally, on the subject of continuing your CPAP journey, you may be wondering just how long that journey may last. There’s no cure for OSA, only treatments and lifestyle changes that can reduce symptoms. So if you want to keep sleep apnoea at bay you need to keep using your CPAP machine – ideally every night, for as long as possible18, as research has shown this boosts the benefits.


Sticking to therapy long-term

Thankfully, there’s lots you can do to help make it easier to stick to therapy long-term. Take tracking for example. The coaching apps mentioned above are not just for the beginning of therapy. Seeing your CPAP performance progress over time can be motivating if you’re feel like you’re flagging! What’s more these apps can also provide tips on solving any minor issues by yourself, as well as instructional videos to help boost your CPAP confidence. This connectivity also allows your care team to monitor your therapy and make adjustments as necessary.

And don’t forget, we’re always here to offer support – explore the rest of our blog for interesting info on all sorts of topics relating to CPAP, OSA and sleep in general. Enjoy the ride!

This blog post contains general information about medical conditions and treatments. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. The information is not advice and should not be treated as such. You must not rely on the information on this website as an alternative to medical advice from your doctor or other professional healthcare provider.

If you have any specific questions about any medical matter, you should consult your doctor or other professional healthcare provider. If you think you may be suffering from any medical condition, you should seek immediate medical attention. You should never delay seeking medical advice, disregard medical advice, or discontinue medical treatment because of information on this website. The views expressed on this blog and website have no relation to those of any academic, hospital, practice, or other institution with which the authors are affiliated and do not directly reflect the views of ResMed or any of its subsidiaries or affiliates.

*ASV therapy is contraindicated in patients with chronic, symptomatic heart failure (NYHA 2-4) with reduced left ventricular ejection fraction (LVEF ≤ 45%) and moderate to severe predominant central sleep apnoea.


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