Q: I recently developed an excruciating pain on the bottom of my foot. One day, I felt fine with no tenderness at all and the next I was unable to put any weight on it without searing pain. There is a ...

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 ...

An epidermoid cyst is a lump under the skin. Epidermoid cysts usually do not require treatment, unless a person wants to have them removed due to cosmetic reasons, or if the cyst becomes infected.