EPR stands for "expiratory pressure relief" and is a feature found on some CPAP machines that reduces the amount of air pressure released by the device during exhalation. This setting makes it easier to exhale against the flow of air while using a CPAP machine, and it can be adjusted from 0-3 in increments of 1. EPR gently lowers the pressure delivered to the user as they exhale, making it easier to breathe out against the air pressure. This feature can be helpful for those who are still adjusting to therapy, having shortness of breath when using their CPAP, or struggling with high-pressure settings. However, its important to note that increasing the EPR setting can reduce the amount of EPAP that is generated, making it easier for the airway to collapse on itself and potentially leading to issues such as lowered blood-oxygen saturation and the development of central sleep apneas and hypopneas. Its recommended to work with a sleep technician to identify the best settings for individual needs.