When you’re awake, your throat muscles keep your airway open so you can breathe. When you fall asleep, your muscles relax which narrows the throat. In normal individuals, air flow is not blocked, but if you have sleep apnea, the breathing passage becomes partly or fully obstructed. This may be due to:

  1. Relaxation of throat and tongue muscles more than usual
  2. Your tongue or tonsils are larger relative to the size of your throat
  3. You are overweight and the extra fat tissue around your windpipe makes it more narrow
  4. The bony structure of your face and skull cause a smaller airway size

Often these features are genetically determined, which is why sleep apnea can cluster in families.

What Causes Sleep Apnea?

Sleep apnea has many different possible causes. In adults, the most common cause of obstructive sleep apnea is excess weight and obesity, which is associated with soft tissue of the mouth and throat. During sleep, when throat and tongue muscles are more relaxed, this soft tissue can cause the airway to become blocked.