Suggest Treatment For Pain In Hip Bone Area

Hi~ I've had constant lower left abdominal/hip pain for the last week, precisely at the hip bone, front and back. Its hard to describe the pain, but it is very uncomfortable, ongoing, and extremely tender to the touch. Neither ice or heat help. I have not had an injury or any surgery and the pain seemed to have come out of the blue. I have no clue as to what it could be, therefore I have no idea how serious it could be. Perhaps a simply muscle strain or something that requires medical attention. I am 40 years old, female, and physically fit. Please help! :-o