I don't know all of the factors involved, but I slept for 12 hours on Sunday. I could not muster any energy, and I am still tired. The medications that I'm on probably cause some of it, but there are to many things involved, and it's not knowable what the cause is. I've come to the conclusion that there are no guesses that can be made. The Kidney disease is probably a part of it, and many things combined. BF