A number of different conditions can cause pain in the general area of the coccyx, but not all involve the coccyx and the muscles attached to it. The first task of diagnosis is to determine whether the pain is related to the coccyx. Physical rectal examination, high resolution x-rays and MRI scans can rule out various causes unrelated to the coccyx, such as Tarlov cysts and pain referred from higher up the spine. Note that, contrary to most anatomical textbooks, most coccyxes consist of several segments: 'fractured coccyx' is often diagnosed when the coccyx is in fact normal or just dislocated at an intercoccygeal joint.

A simple test to determine whether the coccyx is involved is injection of local anesthetic into the area. If the pain relates to the coccyx, this should produce immediate relief.

If the anesthetic test proves positive, then a dynamic (sit/stand) x-ray or MRI scan may show whether the coccyx dislocates when the patient sits.

Use of dynamic x-rays on 208 patients who gave positive results with the anesthetic test showed:

- 31% Not possible to identify the cause of pain

- 27% Hypermobility (excessive flexing of the coccyx forwards and upwards when sitting)

- 22% Posterior luxation (partial dislocation of the coccyx backwards when sitting)

- 14% Spicule (bony spur) on the coccyx

- 5% Anterior luxation (partial dislocation of the coccyx forwards when sitting)

This study found that the pattern of lesions was different depending on the obesity of the patients: obese patients were most likely to have posterior luxation of the coccyx, while thin patients were most likely to have coccygeal .

Activities that put pressure on the affected area are bicycling, horseback riding, and other activities such as increased sitting that put direct stress on the coccyx. The medical condition is often characterized by pain that worsens with constipation and may be relieved with bowel movement. Rarely, even sexual intercourse can aggravate symptoms.