This is a thickening of the outer layer of either one or both lungs. It may occur after benign pleural effusion or develop without the accumulation of fluid. Symptoms are usually gradually increasing breathlessness and the sensation of tightness in the chest. This is due to the lungs and chest wall not expanding fully, and may become disabling.
There is no effective treatment although the prognosis is usually quite good. The patient may remain moderately breathless on exertion for many years.