Hip Inflammation What Could Cause A Sudden, Acute Pain Top Of Hip In Back For Over A Week, Without Any Injury.?

What could cause a sudden, acute pain top of hip in back for over a week, without any injury.? - hip inflammation

I never had an injury, and he can not decide whether it is an inflammation of the muscle tissue or lining of bone or body cavities. Feeling better after a bath or a restful sleep.