Sasha, here's a new thread to discuss OI in those of us that don't have the obvious, classic OI symptoms. I was one of those people who thought I didn't have OI because I don't get dizzy when I stand up, or pass out. I don't have low blood pressure. Surely I don't have OI! Wrong. I have OI, thought to be primarily the result of low blood volume. What's causing the low blood volume? That's still a mystery. Nevertheless, treating low blood volume has substantially improved my ability to function. Things that used to be difficult -- showering, hanging laundry, unloading the dishwasher, climbing stairs -- are no longer a problem. I didn't realize before that those problems could be the result of OI. These two sources of information have helped me: This article, Treating Orthostatic Intolerance in Chronic Fatigue Syndrome (ME/CFS) and The ME/CFS Primer for Clinical Practitioners. I did the Simple Test for Orthostatic Intolerance and took the data to my ME/CFS specialist who referred me to a cardiologist. I took my data and the ME/CFS Primer with the relevant areas highlighted to the cardiologist. He had seen my daughter first, and not believing a healthy looking 21 year old who is not repeatedly passing out could have dysautonomia, he ordered a TTT for her. Her results were sufficiently disturbing that he now takes ME/CFS seriously. He did not have any prior knowledge (ie, negative bias) about ME/CFS, so that was easier than it might have been. He didn't make me do a TTT. He accepted the data I took at home and the information in the ME/CFS Primer. Dr Rey manages my OI treatment with the cardiologist as backup. My daughter's treatment plan is fairly typical, I think. She takes 0.1mg of Florinef and tries take in extra salt and water. She is still somewhat tachycardic, but the docs are reluctant to use meds to slow her heart rate given her age. She could manage her OI better, but it's not causing her any big problems, so she doesn't want to bother. My treatment is on the more extreme end. I take 0.25mg of Florinef, 120mg of verapamil (for tachycardia), 3L (or more) of electrolyte fluid daily. I need to fluid load to compensate for overnight blood volume depletion. I drink 600ml of iced electrolyte water immediately before bed, and another 600ml before I get out of bed in the morning. I stay in bed about 45 mins for my BP and HR to stabilize, but after that I actually feel energetic. I drink another 600ml bolus 6-7 hours after the morning one. The rest of the 3L of fluid I drink over the course of the day. I'm not going to run any marathons, but I'm not tired and can do a lot of small things I couldn't do before OI treatment. It's not a cure for ME/CFS, but treatment could improve quality of life -- something we could all use. I wonder how many other PWME there are, like me, who are significantly impaired by OI but don't realize it.