Respiratory physiology and pulmonary complications in obesity.

Obesity is generally accepted as a global epidemic and the most common metabolic disorder in the world. Obesity affects every organ system but the consequences on the respiratory system are often underappreciated. While the respiratory consequences of being overweight are predominantly mechanical, an inflammatory element has also been proposed. For this discussion, the components of the respiratory system can be divided into the airways, pulmonary parenchyma, pulmonary vasculature, and the upper respiratory tract. This section will discuss respiratory physiology and the mechanisms leading to breathing difficulties in obesity followed by the impact of obesity on commonly occurring pulmonary disorders.