I fell down stairs of a camper last sunday and hurt my right side with bruises and soreness. I don t believe I broke any ribs and was feeling pretty good until this afternoon. I went on a short snowmobile ride and coming down a mountain pain began in the right side, same as where I fell down the stairs, and it s quite severe. How can I tell if it s my kidney and not just muscle strain? The pain is localized and it hurts to bend over and is very tender to touch.