Does anyone know what the main difference is between the two. My exhaustion just lately has been scaring me, its not so much I need to sleep (any more than normal) but I don't have energy to lift things, even my own limbs at times. Also suffering dizziness. I'm quite frightened, feeling very alone. The wife is not supportive at the moment, she just feels shes getting the brunt of it all which I guess she is but I really can't try any more than I am.