SDB (Sleep Disordered Breathing) is the partial or complete occlusion of the upper airway. This causes interruptions in your breathing (apneas).

 

This airway narrowing may be caused by relaxed muscles in the airway, a narrow airway, large tongue or extra tissue in the throat. The pauses in breathing may last from 10 to 60 seconds. When this occurs airway flow is reduced, oxygen levels decrease and CO2 levels increase. This causes an arousal in the brain. The brain lightens the stage of sleep in order to open the airway. Even if the airway is not completely occluded and only partially blocked (hypopnea) an arousal may still occur.

 

These arousals generate increased adrenalin levels. The low O2 levels and higher adrenaline levels caused by SDB puts one at much higher risk for health problems.

 

The chart below is an example of normal sleep stages through the night. Stages of sleep become disrupted with those that have SDB.