When you sleep, your tongue and surrounding throat muscles relax, which helps air flow to your lungs.
If you have OSA, though, your airway is narrow. So when your tongue and surrounding throat tissues relax, sleep apnea can temporarily block the flow of air and cause brief pauses in breathing.
How does sleep position come into play? Lying on your back, for example, can cause your tongue and throat tissues to collapse further, making it even harder for air to flow to your lungs, says Stephen Carstensen, DDS, a dental sleep specialist who treats sleep-related breathing disorders in Bellevue, Washington. This is true even with a CPAP machine.
But other positions can help keep your airway open, making it easier for a CPAP machine to usher air into your lungs and help you get a good night’s rest.