Obesity Hypoventilation Syndrome

Syndrome (OHS)? OHS is a breathing disorder in obese people that leads to low oxygen levels and too much carbon dioxide in your blood. Low oxygen and high carbon dioxide levels may develop because of a condition called hypoventilation during the day (daytime hypoventilation). Hypoventilation means you are not moving enough air in and out of your lungs very well. With OHS, you may also have difficulty sleeping because of obstructive sleep apnea (see ATS Patient Series to read more about Obstructive Sleep Apnea at http://patients. thoracic.org/information-series/index.php). The three main characteristics of OHS are: 1) obesity; 2) daytime hypoventilation (difficulty getting rid of carbon dioxide); and 3) sleep disordered breathing (such as obstructive sleep apnea). OHS is also referred to as Pickwickian syndrome because persons with OHS may have symptoms like those described by Charles Dickens in his essay, The Posthumous Papers of the Pickwick Club.