Written by Dr. Anitha Paderla, MBBS | 
Medically Reviewed by Dr. Sunil Shroff, MBBS, MS, FRCS (UK), D. Urol (Lond) on Feb 07, 2020

Mechanism of Obstructive Sleep Apnea (OSA)

With each arousal event, the muscle tone of the tongue, and the airway tissues, increases. Each time this happens, the obstruction is relieved putting an end to the apneic event. As soon as the patient drifts to sleep, the tongue and soft tissues assumes a relaxed position. This could yet again trigger a partial or complete obstruction in the airway accompanied by snoring.

More commonly, airway obstruction occurs in the common space where the food pipe and air pipe intermix at the back of throat called the oropharynx. Oropharynx includes the soft palate, the base of the tongue, and the tonsils. The factors causing the obstruction are usually multiple, depending on the severity of the condition; they include-

  • The increased deposit of fat around the airway
  • An elongated soft palate
  • An enlarged uvula
  • Decreased muscle tone during sleep
  • The effect of gravity in supine position
  • Some patients have airway obstruction because of a diminutive or receding jaw that results in insufficient space for the tongue.


sunny1 Tuesday, June 3, 2008

See this recent publication that indicates that obstructive Sleep Apnea - Obstructive sleep apnea (OSA) is associated with coronary artery disease (CAD). We hypothesized that OSA is independently related to the risk of CAD or death from any cause. In this observational cohort study, patients referred for OSA underwent polysomnography, and subsequent CAD events (myocardial infarction, coronary angiography or bypass graft surgery) or death were recorded. Patients were divided into exposure (AHI 15) and comparison groups (AHI Increased Risk of Coronary Artery Disease and Death, Shah NA et al New Haven, CT

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