Continuous positive airway pressure is the acronym for CPAP, while Bi-level Positive Airway Pressure is the acronym for BiPAP. They both are machines that help in the treatment of sleep apnea and other respiratory disorders. Though they both perform the same function, they have some differences.
They differ in the aspect of air pressure; CPAP machines usually deliver one level of air pressure while BiPAP has two levels of air pressure. CPAP machines aid breathing by the application of pressure continuously to the airways. While BiPAP would exert a high pressure when patients inhale and give low pressure when the patients exhale.
Extra effort is demanded from the patients to inhale and exhale air with the CPAP machines. Bi-level Positive Airway Pressure is so useful for people who are suffering some lung diseases such as COPD, while Continuous Positive Airway Pressure is okay for people who have severe sleep apnea.