Coccydynia

The coccyx, also known as the tailbone, is the smallest bone situated at the bottom end of the spinal column. The coccyx performs the function of anchoring multiple muscles in the pelvic area, acting as a bone which bears the weight of the body when a person is sitting. Coccydynia is described as sharp or dull pain at the tip of the coccyx and is typically worse whilst sitting down. The most common causes of persistent coccyx pain are direct trauma, caused by a fall or degenerative change. In other cases, the pain is associated with obesity, being underweight or has no identifiable source, and this is known as idiopathic coccydynia.

Coccydynia can be caused referred pain, abnormal curvature, a subluxed or hypermobile coccyx. Rare causes may include infection or a tumor.