Sudden onset sharp pain in coccyx when sitting on bottom. pain causing difficulty when sitting down&standing up.no falls no long term sitting or cycling etc.no trauma at all. what could cause sudden onset pain like this?

Pain over the coccyx can sometime occur without any clear history of injury . It can be due to joint hypermobility , which can be tested for by a rectal exam . Sometimes it is due to degenerative changes in the joints . An xray would reveal any evidence of injury . Usually local heat or cold , painkillers , wedge cushions over the area when sitting , can help to tide over the painful period .