Hi, Still a little new to this forum. I am going to get a (TTT) Thursday 20th for the first time to be tested for Pots. I was diagnosed with CFS and after recently learning about this, I presented the research to my doctor. I found a neurologist who is working with me and has the (TTT) but also have been reading that most people take a Blood Volume test at the same time? IF so, where can I get the name and type of lab work to ask for this? Thank you Grace