**ALL CPAP DEVICES REQUIRE A DOCTORS PRESCRIPTION**
A CPAP machine provides a continuous flow of pressurized air through the mask to prevent the airway from collapsing and causing apnea events. When you purchase a CPAP machine the provider will follow the prescription obtained during your sleep study and adjust the pressure settings on the CPAP machine. Both the industry and users are moving toward auto adjusting CPAP machines which automatically adjust pressures to the lowest pressure necessary on a breath by breath basis. This creates a more natural breathing cycle but improves comfort and compliance. In order for CPAP therapy to successfully treat OSA, a person needs to sleep continuously for a minimum of four hours a night. A Bi-Level machine offers an even more nuanced CPAP therapy by providing inhalation and exhalation pressures to provide further comfort from high exhalation pressure. People who find traditional CPAP therapy challenging, Bi-Level machines make for a alternative to better tolerate therapy.