The intersection of obstructive lung disease and sleep apnea.

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) have synergistic detrimental effects. Their comorbid association leads to compromised gas exchange (hypoxia and hypercapnia) and higher rates of morbidity and death. As our understanding of the pathophysiologic processes of sleep evolves, the relationship between OSA and obstructive lung diseases such as COPD ("overlap syndrome") or asthma ("alternative overlap syndrome") has become more apparent. The pathophysiology of the combined conditions and optimal management are still being defined, but the effect on quality of life and morbidity underscore the importance of proper diagnosis and appropriately tailored management in these patients.