When using a CPAP machine, why do you have so many dreams? Both good and bad dreams, are they normal?

Normally, people with obstructive sleep apnea (OSA) will not have complete cycles of sleep (Sleep stage), especially during deep sleep and dream sleep is absent or very rare. When using a CPAP machine, we will have all levels of sleep. This includes the REM stage, or dream sleep. So frequent dreaming while using a CPAP machine is normal and a good thing.