Left side pain in area of hip bone now radiating to back. don't feel ot when laying down. what is this?

Hip arthritis: Since your pain occurs with weight bearing, hip pathology such as arthritis is a strong possibility. Fracture would be much less likely without trauma. There also is a possibility your pain can be from the lower back radiating to the hip. Arthritis or disc problems in the back could be possible. X-rays and a physical exam are needed. Back issues also may be more painful when up rather then laying