ABSTRACT
Obesity hypoventilation syndrome (OHS) refers to the development of daytime hypoventilation in obese individuals with sleep-disordered breathing in the absence of more likely reasons apart from obesity to explain the presence of awake hypercapnia. While the consequences of excess weight on lung volumes and sleep-disordered breathing obviously play a central role in the development of this disorder, these are not the only factors involved given the significant overlap between those with OHS and individuals who are able to maintain eucapnia despite similar ventilatory loads. A key distinguishing feature of OHS is the impairment in ventilatory control seen in OHS compared to weight-matched controls.
