Can anyone tell me, does Dysautonomia cause severe fatigue? I slept from 3 am last night until 4 pm today. I would get up, get breakfast and go back to bed. I am exhausted, dizzy, can't stand for long. I am weak. Does anyone else know if Dysautonomia can do this? I see a neurologist tomorrow. I am scared as after 30 years of having what is CFS, I have never had this. It's a fatigue that I can't even describe and it's more like severe inability to be "up." as in sitting up, etc. I have POTS so I know that is part of it, but I was not diagnosed by TTT. I was diagnosed by just standing up and sitting down and due to the fact that my BP is 90/54 and sometimes lower. I am just crushingly exhausted and all I want to do is sleep. My MCAS is severe at the moment also.