Back, hip and leg pain that comes and goes. Could this be arthritis?

that sounds a little like the pain that i had. i ended up having reconstructive hip surgery because of hip dysplasia. i had pain from my upper /lower back down my leg and in my hip. the pain was really bad when i walked a bunch but okay when i was lazy. it also hurt when i sat for a long time. you might want to get your hips checked out by a hip specialist because the longer you wait to get it fixed the less can be done to fix it. i also had a slipped disk which hurt a lot. it was my L5 and it was pinching my sciatic nerve causing pain all the way down my leg and was making my leg go numb. i ended up having back surgery to fix it and havent had any more problems with it since. i suggest you go to the doctor because it took 4 years for them to find something wrong with my hip!