A cyst is a sac or cavity that may be filled with pus, semi-solid material, or air. It doesn’t usually cause pain until it gets large. An abscess is a painful, red infection that’s filled with pus. A ...

A cyst is a sac of tissue containing fluid or air that can form in many areas of the body. Cysts often do not need to be removed unless they are causing pain or other problems. There are several ...