A pilonidal cyst is a fluid-filled defect. It is found at the base of the spine, or "tailbone" area.
The terms cyst, sinus, and abscess refer to different stages of the disease process.
* Cyst—not infected
* Abscess—pocket of pus
* Sinus—opening between a cyst (or other internal structure) and the outside
When a pilonidal cyst is infected, it forms an abscess, eventually draining pus through a sinus. Pilonidal cysts are harmless until they get infected. At this point they form an abscess that causes pain, a foul smell, and drainage. This is more likely to occur in young Caucasian men with a lot of hair in the region.
This condition is not serious, but since it is an infection like a boil or carbuncle, it can enlarge and become uncomfortable. Therefore, it should be treated.
