Sleep apnea is a serious health condition in which your breathing stops occasionally while you sleep. This breathing disorder is known to contribute to severe health conditions such as kidney disease, diabetes, and even stroke. Thankfully, with continuous positive airway pressure, or CPAP therapy, the condition is very treatable. CPAP treatment uses a machine to deliver forced air through a face mask. This forced air is essential because it keeps your airways wide open and allows free air to move in and out of your lungs while you sleep. For most people, CPAP treatment is tolerable and comforting, but, for a small population, the pressured air is intolerable.

Why is Pressured Air Sometimes Uncomfortable?

CPAP machines work by keeping a constant pressure flowing through your windpipe while you sleep. This means that whether you are breathing in or out, the pressure being blown through your sleep apnea mask is the same. For some CPAP users, this constant pressure is too much to tolerate, and they feel as though they’re fighting a wind storm in order to exhale. If you find yourself uncomfortable exhaling against your prescribed CPAP pressure, don’t give up on your treatment. There are options available to make your therapy more tolerable.

C-Flex Pressure Relief Technology

The engineers at Philip’s Respironics have developed a component for their CPAP machines which allows for comfortable exhalation even if your doctor has prescribed you with a high pressure level. C-Flex Pressure Relief Technology is a computer based algorithm installed on many of the Respironic line CPAP machines available at This algorithm works by lowering the delivered pressure when the computer inside your CPAP machine senses that you’re getting ready to exhale. Once you’ve finished breathing out, pressure is restored to your prescribed setting. Many of these CPAP machines are also built with a ramp feature that slowly increases pressure overtime. This slow increase will allow you to fall asleep with a low pressure setting so that you’re never fighting forced air while awake.

 Expiratory Pressure Relief

More traditional ramp features work by slowly increasing pressure over a set amount of time. ResMed’s AirSense CPAP line works differently. This ramp feature works not by a time setting, but by sensing when you actually fall asleep. Best of all, this CPAP has a Expiratory Pressure Relief mechanism that, like the C-Flex, allows you to exhale against the delivered forced air. ResMed’s EPR feature works by noticing when your air pressure begins to change a second or two into exhalation. This dynamic feature is another option for improving your comfort level during CPAP therapy. The EPR technology allows this CPAP to be exceptionally quiet meaning your partner won’t be kept awake while you sleep.

Where to Find C-flex or EPR Options

At, you’ll find both ResMed and Respironic’s CPAP product lines. The respiratory professionals on staff are available by phone to help you find the perfect CPAP products and accessories to stay comfortable during your treatment. Whether you’ll be happiest with a ramp feature, the C-Flex, or ResMed’s EPR technology, has got you covered.