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)

Sleep Apnea Throat

Obstructive Sleep Apnea is caused by repetitive upper airway obstruction during sleep as a result of narrowing of the breathing passages.

When a person is awake the airway muscle tone helps to keep the airways patent. Decreased airway muscle tone during sleep, and the pull of gravity in the supine position, results in some prolapse of the airway structures and further decrease its size. This can impede airflow during respiration. Snoring can occur during the initial stages, caused by partial obstruction in the airway. As tissues collapse further or the patient rolls over on his or her back, the airway may become completely obstructed.

When the nature of obstruction is partial it is termed as hypopnea, whereas, a complete obstruction in the airway is called Apnea. Both hypopnea and apnea cause disruption in victims’ sleep several times during night, though the disturbance may go unrecognized by patients. The obstructive episodes are often associated with a reduction in blood oxygen levels.


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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