What a CPAP machine does

A CPAP machine is a small bedside device that gently pushes air into your nose or mouth while you sleep. CPAP stands for "continuous positive airway pressure." The machine keeps your airway open so you can breathe steadily through the night without pauses or gasps. It does not add oxygen to the air—it straightforward maintains pressure so your throat does not collapse during sleep.

Most people use a CPAP because they have obstructive sleep apnea (OSA), a condition where the throat muscles relax and block the airway repeatedly during sleep. Each time the airway closes, your brain wakes you up just enough to gasp for air. You may not remember these awakenings, but they happen dozens or hundreds of times per night, leaving you exhausted during the day. A CPAP prevents those collapses from happening in the first place.

The machine itself is about the size of a toaster, sits on your nightstand, and connects to a mask you wear over your nose, mouth, or both. A hose carries the pressurized air from the machine to the mask. You turn it on when you get into bed and it runs all night.

Key Takeaways

  • A CPAP machine pushes steady air pressure into your airway to prevent it from collapsing during sleep, which is the main symptom of obstructive sleep apnea.
  • You will need a sleep study and a doctor's prescription before you can get a CPAP; the study measures how many times per hour your airway closes.
  • CPAP machines cost between $500 and $3,000 depending on features, and most insurance plans cover them if a doctor prescribes one for sleep apnea.
  • The mask is the most important part—finding one that fits comfortably takes trial and error, and many people try several styles before finding one they can wear all night.
  • Most people need two to four weeks to adjust to wearing a mask and using the machine regularly, and starting with a lower pressure setting helps.

How to know if you need one

The only way to know whether you have sleep apnea is to have a sleep study. Your doctor can order one if you report symptoms like loud snoring, gasping awake, daytime sleepiness even after a full night in bed, or waking with a dry mouth or sore throat. You do not need to have all of these—even one is worth mentioning.

A sleep study can happen at a sleep lab (you spend a night in a clinic hooked up to monitors) or at home (you wear a small portable device that records your breathing). The study counts how many times per hour your airway closes. If the number is high enough, your doctor will prescribe a CPAP and tell you what pressure setting to use.

Sleep apnea is common but often undiagnosed. If you snore loudly or your bed partner says you stop breathing during sleep, that is worth mentioning to your doctor even if you do not feel tired during the day. Untreated sleep apnea raises the risk of heart attack and stroke over time.

What a CPAP setup includes

The basic setup has four parts: the machine itself, a hose, a mask, and a humidifier chamber. The machine is a small box with a motor that pulls in room air, filters it, and pressurizes it. The hose carries that air to the mask. The humidifier adds moisture to the air so it does not dry out your nose and throat overnight—this is optional but most people find it more comfortable.

The mask is the part you actually wear, and it comes in three main styles. A nasal mask covers just your nose and is the smallest and lightest option. A full-face mask covers your nose and mouth and is better if you breathe through your mouth or have a blocked nose. A nasal pillow is the smallest of all—just two small tubes that sit in your nostrils—and works well if you move around a lot in bed or feel claustrophobic.

Masks come in different sizes and brands, and fit varies widely. Most people try at least two or three before finding one they can wear comfortably for eight hours. Your supplier or doctor can help you try different options.

Cost and insurance coverage

A CPAP machine typically costs between $500 and $3,000 depending on the brand and features. Basic models are simpler and cheaper; fancier ones may have data tracking, quieter motors, or automatic pressure adjustment. Most insurance plans, including Medicare, cover CPAP machines if a doctor prescribes one for sleep apnea, though you may have a copay or coinsurance.

Some insurance plans require you to use the machine for a certain number of hours per night (often four hours) for a certain number of days per month (often 21 days) before they will pay for it. Your supplier can tell you what your insurance requires. If you do not have insurance, some suppliers offer payment plans.

Masks and hoses wear out and need replacing every few months to a year. Replacement masks typically cost $50 to $150 each, and hoses cost $20 to $50. These are usually covered by insurance if the original machine was covered.

Getting used to wearing a mask

Most people find the mask uncomfortable at first. It takes pressure on your face, it can feel claustrophobic, and you have to get used to air blowing into your nose or mouth. The adjustment period is usually two to four weeks, though some people adapt faster and some take longer.

The best way to speed adjustment is to start with a lower pressure setting than your final prescription calls for, then gradually increase it over a few nights. Many machines have a "ramp" feature that starts at a low pressure and slowly climbs to your target pressure over 20 to 45 minutes, which makes falling asleep easier. Wearing the mask during the day while you are awake—even just for 10 or 15 minutes—also helps you get used to how it feels.

If a mask is uncomfortable, tell your supplier. A different size, style, or brand may work better. Leaks around the mask are common at first and usually mean the fit is not quite right, not that the mask is defective. Adjusting the straps or trying a different size often solves the problem.

What happens after you start using one

Most people notice a difference within a few days to a week. You may feel more alert during the day, sleep more soundly at night, or stop waking with a dry mouth. Some people feel the change when ready; others take longer to notice. If you do not feel better after two weeks, tell your doctor—your pressure setting may need adjustment, or there may be another reason for your daytime tiredness.

CPAP machines record data about how many hours you used it, how many times your airway closed despite the machine, and other details. Your doctor can read this data at your next visit to see how well the machine is working for you. If your airway is still closing frequently, your pressure may need to be higher.

You will need to clean your mask and hose regularly—usually once or twice a week with mild soap and water—to prevent mold and bacteria buildup. The machine itself does not need cleaning, but the filter should be checked monthly and replaced when it looks dirty.

Alternatives if CPAP does not work for you

Some people cannot tolerate wearing a mask every night, even after weeks of trying. If that is you, other options exist. A BiPAP machine uses two pressure levels (one for breathing in, one for breathing out) and feels less forceful to some people. An APAP machine automatically adjusts pressure throughout the night based on your breathing, which some people find more comfortable.

Dental devices that move your lower jaw forward can also treat mild to moderate sleep apnea by opening your airway. These require a prescription from a dentist and are custom-made to fit your mouth. They work for some people but not all.

Weight loss, sleeping on your side instead of your back, and avoiding alcohol and sedatives before bed can reduce sleep apnea symptoms, though they rarely cure it completely if you have moderate to severe apnea. Surgery to remove tissue from the throat is an option in rare cases, but it is not common and does not always work.

Frequently Asked Questions

Can I use a CPAP while traveling?

Yes. CPAP machines run on standard household current (110 volts in the US), and most are small enough to fit in a suitcase. If you are traveling internationally, you may need a voltage converter. Some people use battery packs or car adapters for camping or road trips. Ask your supplier what options are available for your specific machine.

What if I have a cold or stuffy nose?

A stuffy nose makes CPAP uncomfortable because the air cannot flow freely. Using a saline rinse or decongestant spray before bed can help. Some people use a heated humidifier on a higher setting. If you are very congested, it is okay to skip a night, but try to use the machine as soon as you can breathe again.

Do I have to wear the mask every single night?

Ideally yes, but missing a night occasionally will not hurt you. Your airway will collapse again that night, but one night of apnea does not cause lasting harm. The benefit of CPAP comes from using it consistently—most nights of the week, every week. If you are struggling to use it regularly, talk to your doctor or supplier about what is getting in the way.

Can my bed partner use my CPAP machine?

No. CPAP machines are prescribed based on your individual sleep study results and pressure needs. Someone else's pressure setting could be too high or too low for another person and would not help them. Each person with sleep apnea needs their own machine and their own prescription.

Will I need to use a CPAP forever?

Sleep apnea is usually a long-term condition, so most people use a CPAP for years. However, significant weight loss can reduce sleep apnea severity enough that you might need a lower pressure or use the machine less often. Talk to your doctor about whether your condition has changed if you have lost weight or made other major lifestyle changes.