Question

What prevents you from suffercating when you ly down or fall asleep

Answer 1

When the body senses it's not getting enough oxygen during sleep, it forces an awakening. At this time, the breathing airways open and breathing resumes. Because of this mechanism, you stand no chance of suffocating in your sleep.

Step-by-step explanation:

Answer 2

When lying flat, people often find it difficult to breathe. Orthopnea is the medical term for this. People who are affected by this will often need to sleep with their heads propped up on pillows.