oxygen level

What is Obstructive Sleep Apnea (OSA)?
People with OSA experience recurrent episodes during sleep when their throat closes and they cannot suck air into their lungs (apnea). This happens because the muscles that normally hold the throat open during wakefulness relax during sleep and allow it to narrow. When the throat is partially closed and/or the muscles relax too much, trying to inhale will suck the throat completely closed and air cannot pass at all. This is an obstructive sleep apnea episode.

A cessation of breathing must last 10 seconds or more to be called an apnea. Obstructive apnea episodes can last as long as two minutes and are almost always associated with a reduction in the level of oxygen in the blood. When an individual is in the midst of an obstructive sleep apnea episode, as long as sleep continues, the apnea continues. It is only terminated and the victim's life is saved by waking up. This arousal instantly increases the activity of the muscles of the tongue and throat muscles that enlarge the airway. The victim will be able to breathe and to once again fill the lungs with life-giving oxygen. This cycle may be repeated hundreds of times a night while the sufferer has no idea it is happening.