Both physical characteristics and lifestyle choices can lead to or add to an OSA condition. Obesity is frequently associated with OSA, but even persons of average weight can develop this condition. OSA becomes more common with age, and it estimated that one in 25 middle-age men and one in 50 middle-age women suffer from OSA. There also seems to be some hereditary predisposition to OSA.

Any structural abnormality in the face, skull, or airways that cause some obstruction or collapse in the upper airways and reduce air pressures can lead to OSA. Among the most likely structural cause are abnormalities in tissue that lie between the back of the mouth and the esophagus. Enlarged soft palates have been particularly associated with many cases of sleep apnea.

Other causes researchers have identified associated with sleep apnea include:

  • Facial or skull abnormalities, overbite, narrow upper jaw, receding chin and high elevated palates
  • Large tongue
  • Overgrown tonsils or adenoids
  • Having a large neck circumference
  • Nerve, metabolic, and mechanical abnormalities
  • Obesity
  • Abnormal sleep behaviors
  • Smoking and alcohol use