J94: Other pleural conditions

J94.1: Fibrothorax

The lungs are surrounded by a smooth membrane. A smooth membrane like this is also located inside the ribs. Both membranes cling to each other via a small amount of fluid. Through the suction of the fluid between the membranes, the lungs follow the movements of the chest while breathing. The lungs then alternately expand and contract. Air for breathing flows into the lungs and out again during these movements.

In your case, the smooth membrane around the lungs is thickened in some places.