What does it mean when your tailbone hurts and is red around it, but you're not sure if it's the bone or the skin? what causes it?

Pilonidal cyst: Unless you have a herpes outbreak, diabetes with excessive tissue breakdown (decubitus ulcer) the most likely diagnosis is a pilonidal cyst which may be caused by an ingrown hair, excessive sweating, an inborn "dimple" that gets infected. Treatment may be excision, antibiotics, or a new "fibrin" glue. Check with a local g.P or internist.