Sleep Apnea

Sleep Apnea is one of the sleep respiratory disorder. It’s severity is classified by the frequencies of pauses of breathing. Base on the causes of apnea, sleep apnea consists of 3 main categories 



  • Obstructive Sleep Apnea
  • Central Sleep Apnea
  • Mixed/ Complex Sleep Apnea



Obstructive Sleep Apnea

The most common type of sleep apnea, up to 84% of cases fall into this category. It is caused by physical blockage of upper airway, including excess fat tissue, anlarged lymphoid tissues, structural reason, etc. Low muscle tone during sleep (esp. deep sleep) will give rise to blockage and thus causes breathing difficulties.

Obstructive Sleep Apnea
  • Normal upper airway (left)and physically blocked upper airway (right)click to zoom

Central Sleep Apnea

Occurs when upper airway is not blocked but nervous system fails to signal muscles to breathe. Thus causes pauses in breathing. Less than 1% cases belong to central sleep apnea, mostly patients who had stroke or brain damage(s) before.

Central Sleep Apnea

Mixed Sleep Apnea

Mixed Sleep Apnea occurs when someone has both obstructive and central sleep apnea. About 15% cases belong to mixed sleep apnea.

Mixed Sleep Apnea


Do I have sleep apnea?
What health effects may be occur if sleep apnea untreated?
What are the high risk groups?
Besides the 3 types of apnea, what other events will lead to sleep apnea syndrome?
How severity of sleep apnea is classified?