pleural effusion

Large right lung pleural effusion
A pleural effusion is excess fluid that accumulates in the pleural cavity, the fluid-filled space that surrounds the lungs. This excess fluid can impair breathing by limiting the expansion of the lungs.

A wide range of things can cause a pleural effusion. Some of the more common ones are:

Leaking from other organs: This usually happens if patient have congestive heart failure, when the heart doesn't pump blood to body properly. But it can also come from liver or kidney disease, when fluid builds up in body and leaks into the pleural space.

Cancer: Usually lung cancer is the problem, but other cancers that have spread to the lung or pleura can cause it, too.

Infections: Some illnesses that lead to pleural effusion