SUMMARY
Abstract: Obstructive sleep apnea (OSA)-induced biological changes include intermittent hypoxia, intermittent hypercapnia, intrathoracic pressure changes, and sympathetic activation and sleep fragmentation. OSA can cause metabolic dysregulation, endothelial dysfunction, systemic inflammation, oxidative stress and hypercoagulation, and neurohumoral changes. Important comorbidities associated with OSA are cardiovascular system i.e. hypertension, cardiac arrhythmias, coronary artery disease, cardiac failure and stroke, respiratory system i.e. pulmonary hypertension, asthma ,COPD, central nervous system i.e. erectile dysfunction, seizure disorders, strokes, psychiatric illness and other systemic diseases like obesity, sudden infant death syndrome, chronic renal failure, diabetes mellitus, GERD. The diagnosis of OSA is based on polysomographic studies. PAP treatment has been found to have beneficial effects in many of these consequences. There is also a need to identify other modalities of treatment. Certainly, the treatment of OSA can greatly improve or even revert some of the co morbid conditions.Keywords: Sleep apnea, Co-morbid, Asthma, Cardiovascular, Obesity, Diabetes, Epilepsy, GERD, Erectile.