Pickwickian syndrome is the historical name of obesity hypoventilation syndrome (OHS). Components of OHS are obesity, diminished lung capacity, obesity, and absence of a mechanical, metabolic, or neuromuscular explanation for inadequate breathing. Although the mechanism of the disease is not known precisely, it is estimated that the typical alveolar gas exchange is disrupted due to obesity, and the oxygen/carbon dioxide balance in the blood of the person is impaired.