I am asking for anyone who is experiencing this to reply.I am on amitriptyline at bedtime,which is to help me sleep and it was working with a lot of the pain I was having. About 4 weeks ago, my husband started 2 weeks of working the night shift.It was temporary,and after a few days I was used to it,BUT after the first week,I started getting a lot of very heavy agonizing pain in my legs.I am now back at a normal sleeping pattern--sleeping nights, and the pain is still there! I find walking up stairs extremely painful and I feel totally exhausted again.Could this be a flare up? or from changing my sleeping pattern? I am so uncomfortable even when sitting.I cannot stop standing up and moving my legs around.I will bring this up to my dr in 2 weeks,but for now any help would be appreciated. I really would like to know how to distinguish a flare up from regular pain.Thanx!