Continuous Positive Airway Pressure, or CPAP, has proven to be the most effective in the management of OSA. Using a small flow generator combined with computer technology, a threshold pressure is applied to the patient airway by way of a nasal mask. When used as directed, the patient is able to attain REM sleep, which is associated with normal sleep patterns. The results can be dramatic. The patient no longer experiences fatigue and daytime sleepiness and is able to function with much higher energy levels, and greater quality of life.