What Causes Numbness And Sweating On Foot And Leg?

My friend might have some sort of nerve damage. She has a numb foot and leg. sometimes this is affecting both her legs. When she can feel them they have pins and needles. They can hurt. Her feet are sweating but are also cold to touch. Her doctors have not given her much advice or comforting words. What should she be doing about her problems? They seem to be getting worse and affecting her sleep.