APAP vs CPAP: Is Auto CPAP Right for You?

CPAP is often used as an umbrella term for all sleep apnea machines, so you might be surprised to find that there are a handful of options available to you! 

If you’ve been diagnosed with sleep apnea, you may hear the terms CPAP, APAP, and BiPAP. These are all types of breathing machines that use positive air pressure (PAP) to help sleep apnea patients breathe during sleep. 

While all of these PAP machines use pressurized air, it’s no exaggeration to say the differences can be life changing. So how do you know which one is right for you? 

Today we’ll explore what APAP therapy is, how it differs from CPAP therapy, and who should consider an APAP machine.

What Is APAP?

APAP stands for “Automatic Positive Airway Pressure” and is a type of therapy used to treat Obstructive Sleep Apnea (OSA). An APAP machine provides a stream of pressurized air that prevents your upper airway from collapsing during sleep. 

The “automatic” part of APAP refers to “auto-adjusting” or “auto-titrating”– a fancy way of saying that the machine can determine its own pressure settings, and even adjust them throughout the night. 

‘Titration’ means to determine the specific pressure needs for your CPAP therapy. Though an APAP is self-titrating– meaning it can adjust its own pressure settings– a doctor or healthcare professional will need to determine the machine’s pressure range through a sleep study.

You may also see these machines referred to as AutoPAP, Auto CPAP, or self-adjusting CPAP.


How is APAP different from CPAP? There are several ways, but the most important is the APAP machine’s ability to increase or decrease your airflow based on your breathing pattern. Simply put, a CPAP machine provides one fixed pressure setting all night long, while an APAP can adjust your air pressure as needed. 

CPAP stands for “Continuous Positive Airway Pressure”, and– as you may have guessed from the name– it provides a continuous flow of air at a steady pressure. CPAP machines are the most commonly prescribed type of PAP machine because they are often the most effective. However, some CPAP users find it difficult to exhale against high pressure air, while others may have differing air needs throughout the night. This is where an APAP machine has the advantage. 

Like a CPAP, an APAP machine also provides a continuous stream of air, but as it does so it’s also measuring your resistance against that airflow, watching for changes in your breathing pattern. Advanced algorithms can use this information to detect snoring, apnea/hypopnea events, and even mask leakage. The APAP then adjusts the pressure level to help keep you breathing naturally. 

If, for example, you change sleeping positions and begin to snore, your APAP can provide a higher pressure to prevent apneas. Or if the machine detects you’re having difficulty exhaling, it can lower pressure to a gentler, more comfortable level. This way you only ever receive the amount of airflow you need.


An APAP machine is not the same as a BiPAP machine. Although both provide different levels of air pressure, a BiPAP still relies on fixed pressure settings

BiPAPs, or bilevel CPAP machines, deliver two set pressure levels. A higher pressure setting for inhalation, and a lower pressure for exhalation. However, those set levels remain constant throughout the night. 

BiPAP machines are usually prescribed for sleep apnea patients who have additional health concerns. These may be other sleep disorders, such as central sleep apnea, or cardio and pulmonary concerns, like COPD, or a history of congestive heart failure.

Who Should Consider an APAP Machine?

When purchasing a PAP machine of any kind your prescription will need to include the type, so if you’re considering an APAP machine, you’ll need to discuss that with your doctor. You may benefit from APAP therapy if you experience one or more of the following:

  • You have difficulty adjusting to or tolerating standard CPAP therapy. Most people need some time to get used to CPAP therapy, but some simply can’t tolerate a continuous airflow.

    An APAP machine delivers lower pressure while you fall asleep and higher pressure only when needed. If you have difficulty breathing against or falling asleep with a standard CPAP machine, an APAP may help you adhere to your therapy. 
  • You experience chronic allergies or nasal congestion. Allergies and congestion cause swelling and inflammation in your airways, which can make apnea worse. This means you’ll need greater airflow to keep your therapy effective.

    With an
    APAP, your machine will adjust when you’re feeling under the weather. 
  • You experience noticeable weight loss or gain. Excess body weight and obesity can worsen sleep apnea. The extra tissue can narrow your airways and contribute to airway collapse.

    On the other hand, even
    modest weight loss can lead to a significant decrease in the number and severity of apneas. So when you gain or lose weight your air pressure needs will change too. An APAP machine will automatically accommodate changes that fall within your original pressure range. 
  • You frequently change sleeping positions or toss and turn. Sleeping on your stomach or back can make your apnea worse, as your upper airway is now fighting gravity too. So if you’re an active sleeper and change sleeping positions often, you may also be changing your airflow needs often.

    An APAP machine can account for your tossing-and-turning, giving you higher pressure when needed, and lower pressure when allowed.

Your sleep study shows an increase in AHI during REM sleep. Your breathing pattern changes during the different stages of sleep and that’s normal, but some sleep apnea patients may have longer and more severe apneas during REM.

To prevent those severe apneas, a fixed pressure CPAP would need to be set to a higher pressure all night long. An APAP, on the other hand, could increase the pressure only when necessary.

Who Should NOT Consider an APAP?

With all of the benefits an APAP machine offers, you may be wondering why anyone would stick with a standard CPAP! There are a few reasons to consider before making your decision…

  • APAP machines tend to cost more. APAP devices feature advanced technology, so their average price can be a few hundred dollars more than a comparable fixed-pressure CPAP.

    If it makes it easier to use your PAP therapy, it may be worth it, but we all have our budgets.
  • Your insurance may require you to try CPAP first. Some insurance providers are reluctant to cover an APAP machine when a more affordable CPAP machine may be more effective in the long run.

    Your Aeroflow Sleep Specialist can tell you what machines your plan will cover before you decide.
  • Some people are sensitive to pressure changes. Some CPAP users report that the adjustments in airflow wake them during the night. Newer APAP machines are designed to make changes more gradually to avoid this, but if you’re sensitive to changes in air pressure, you may find yourself happier with a standard CPAP machine.
  • Certain health conditions prevent the use of APAP therapy. If you have certain heart or respiratory issues, APAP therapy may not be right for you.

    Always talk to your doctor or healthcare provider before making any changes in your sleep medicine routine.

APAP Through Insurance

If you’re interested in considering APAP therapy, Aeroflow Sleep can help! Your personal Aeroflow Sleep Specialist will reach out to your doctor and your insurance provider to make sure your prescription and policy will cover an APAP device

Don’t let sleep apnea cost you another night! Reach out to Aeroflow Sleep today.