How Does CPAP Work
CPAP Delivers Constant, Pressurised Air into the Airway During Sleep
CPAP (Continuous Positive Airway Pressure) therapy is widely recognised as the gold standard for treating obstructive sleep apnea, and it’s easy to see why: it’s simple, effective, and non-invasive.
But what does CPAP actually do once you put on the mask and drift off to sleep? Let’s unpack the process so you can understand exactly how this therapy works to keep you breathing easy all night long.
At its core, a CPAP machine is designed to maintain a steady, gentle flow of pressurised air that acts like an invisible “splint” for your airway. This continuous airflow prevents the soft tissues at the back of your throat—like your tongue and soft palate—from collapsing inward, which is the main cause of blocked airflow in obstructive sleep apnea. By holding your airway open, CPAP ensures that oxygen can move freely into your lungs, so you breathe regularly and deeply throughout the night.
The process starts with a small motorised unit that draws in room air and filters out dust and allergens. This air is then pressurised and delivered through a flexible tube and a well-fitted CPAP mask. The mask forms a crucial seal around your nose, mouth, or both, depending on the mask style you use. When the machine is switched on, the air is delivered at a pre-set pressure level or adjusted automatically, depending on the machine type. This continuous flow of air gently pushes against your airway walls, preventing collapse and keeping your breathing stable and consistent.
Air Pressure Settings Are Calibrated for Effectiveness
One of the most important factors in CPAP therapy’s success is getting the pressure just right. Think of your CPAP machine as a custom-tailored suit—while the basic design is the same for everyone, the exact fit and adjustments make all the difference. The air pressure delivered by your machine is measured in centimetres of water (cm H₂O) and represents the precise amount of force needed to keep your airway open throughout the night.
Typically, your sleep specialist will determine the right pressure for you during a sleep study (also known as a titration study). During this test, specialists monitor your breathing, oxygen levels, and sleep stages to identify the minimum pressure required to prevent your airway from collapsing. This pressure becomes your prescription and is programmed into your CPAP machine to ensure consistent, effective therapy.
Modern CPAP devices, such as the ResMed AirSense 11 AutoSet, often include auto-titrating technology. This means they continuously monitor your breathing throughout the night and automatically adjust the pressure up or down in real time, depending on your needs. For example, if your airway tends to collapse more when you sleep on your back or during deeper sleep stages, the machine will respond by increasing the pressure slightly to keep your breathing steady. Conversely, it may lower the pressure when your airway is more stable, making therapy more comfortable.
Having the right pressure setting is critical for therapy effectiveness. Too low, and the airway might collapse, leading to apnoea events and poor sleep quality. Too high, and you might experience discomfort, bloating, or difficulty exhaling. That’s why it’s so important to have your therapy settings checked regularly.
Philips Respironics DreamStation Auto CPAP Machine with Humidifier
Certain Adjustments Help Optimise Comfort and Fit
Getting used to CPAP therapy can be challenging at first. After all, sleeping with a mask and pressurised air might feel foreign, especially in the beginning. That’s why modern CPAP machines come equipped with comfort features designed to make therapy as natural and easy to tolerate as possible. These small adjustments can make a huge difference in your long-term success with CPAP therapy.
One key feature is ramp time, which allows the machine to start at a lower pressure and gradually increase to your prescribed setting as you drift off to sleep. This gentle approach helps prevent the sensation of overwhelming airflow that some users find uncomfortable. It can make those first minutes in bed more relaxing and set you up for a smoother transition to sleep.
Another valuable feature is expiratory pressure relief, known as EPR (Expiratory Pressure Relief) in ResMed devices or Flex in Philips models. This setting reduces the pressure slightly when you exhale, making breathing feel more natural and less forced. It’s particularly helpful for users who find it challenging to exhale against higher pressures.
Humidity is another game-changer. Most modern CPAP machines, including the ResMed AirSense 11, come with built-in heated humidifiers. These add moisture to the airflow, preventing dryness, irritation, and congestion in your nose and throat. Dry air can lead to nosebleeds, sore throats, and even sinus issues if not managed properly. Heated humidifiers are often adjustable, so you can tailor the level of moisture to your comfort. Pairing your humidifier with heated tubing helps maintain a consistent temperature, preventing condensation (known as “rainout”) inside the tube.
Finding the right mask is crucial too. CPAP masks come in different styles—nasal masks, nasal pillows, and full-face masks—each with its own advantages. Nasal masks cover the nose and work well for most users. Nasal pillows sit just inside the nostrils and offer minimal contact, great for those who feel claustrophobic. Full-face masks cover both the nose and mouth, ideal for mouth breathers or people with nasal congestion.
Real-world tip: Don’t settle for a mask that feels uncomfortable or leaks air. At Sove CPAP Clinic, we offer mask trials and expert fittings to help you find the perfect match. Remember, comfort is key to sticking with therapy every night, and the right adjustments can make all the difference between giving up and sleeping soundly.
Follow-Up Consultations Ensure Your CPAP Therapy Remains Effective
CPAP therapy isn’t just about plugging in the machine and forgetting about it. Like any long-term health treatment, it requires ongoing monitoring and support to ensure it remains effective and comfortable. That’s where follow-up consultations come in.
At Sove CPAP Clinic, we know that your sleep apnea therapy needs can change over time. Weight changes, nasal congestion, mask wear and tear, and even lifestyle changes can all impact how well your therapy works. That’s why regular check-ins with your sleep specialist or CPAP provider are essential.
Frequently Asked Questions
What happens during obstructive sleep apnea?
Obstructive sleep apnea occurs when the muscles in the back of your throat relax too much during sleep, allowing the airway to collapse and block airflow. This can lead to repeated pauses in breathing, fragmented sleep, and lower oxygen levels. Over time, untreated sleep apnea can contribute to serious health issues, including high blood pressure, heart disease, and daytime fatigue. CPAP therapy prevents this airway collapse by delivering continuous pressurised air that keeps the airway open.
What are the components of a CPAP system?
A CPAP system includes the main device unit that generates pressurised airflow, an air filter to keep the air clean, a humidifier chamber to add moisture, tubing that delivers air from the machine to the mask, and the mask itself (which could be nasal, nasal pillows, or full-face). Most machines also include a power supply and often a data card or modem for recording therapy information. These components work together to deliver effective therapy and should be maintained regularly for best results.
What should users expect when starting CPAP therapy?
When starting CPAP therapy, it’s common to experience some initial discomfort, such as feeling claustrophobic, experiencing dryness, or struggling with mask fit. These issues usually improve as you get used to the therapy. Within a few nights to weeks, most users notice better sleep, more energy, and reduced daytime drowsiness. Using humidification and ramp features can enhance comfort. It’s important to stick with the therapy every night, even if it feels challenging at first. Sove CPAP Clinic is here to help with mask fitting, pressure adjustments, and troubleshooting any issues that arise.
How is the pressure level determined?
The pressure level for your CPAP therapy is usually determined through a sleep study, where specialists observe your breathing patterns and determine the minimum pressure needed to prevent airway collapse. Some patients start with an auto-titrating machine that adjusts itself to find the ideal pressure over time. This data helps specialists fine-tune your prescription to ensure effective therapy. If you notice changes in your health, weight, or comfort, it’s important to consult your clinician as your pressure needs may change over time.
What happens if CPAP turns off while sleeping?
If your CPAP machine stops during the night—due to a power cut, technical issue, or accidental mask removal—you might experience the return of apnea events. Many modern devices, like the ResMed AirSense 11, have auto-restart features that resume therapy once you begin breathing into the mask again. If you wake up and find the machine off, simply turn it back on. If this happens frequently, contact Sove CPAP Clinic for troubleshooting support.
Can you ever stop wearing a CPAP?
CPAP therapy treats, but does not cure, obstructive sleep apnoea. Most people need to use CPAP every night to maintain its benefits. Some users may explore alternative treatments, such as weight loss, dental appliances, or surgery, depending on their specific condition. However, any decision to stop using CPAP should always be made with guidance from a sleep specialist. It’s important to weigh the risks and benefits carefully, as untreated sleep apnea can have serious health consequences.