Hello All, I'm new to this site and have yet to actually be dx'd with POTS. However it is suspected as I passed out within 5min of a tilt test, Hx of tachycardia, fainting, nausea, lightheaded, extreme fatigue, etc etc. This has been going on as long as I can remember. Anyway, I had an episode last night. I felt nauseated all of a sudden and just progressed downhill from there. I couldn't help but notice that I had to pee like crazy! I emptied a full bladder, then shortly after another and another. This is a common occurrence for me. I realise that losing lots of fluid is only making the situation worse so I always push fluids but can't seem to hang onto it! I end up getting up to pee it all out every couple hours at night. Even with high electrolyte content it takes quite a while to feel normal again. I almost passed out last night and had to lay down on the floor after one of my trips to the loo. This morning still felt aweful, layed down on the floor, put on my compression stockings, drank more fluids and took Modafinil ( a med prescribed for mild narcolepsy). I see that it is being used in a trail for POTS so I have started to use it more to tx POTS symptoms since I'm sceptical I have narcolepsy. I was able to come around and make it through work ok today - athough very tired. I would love to know what triggers the sudden fluid loss, and if anyone has experience with this same phenomenon? Also, is anyone else taking Modafinil? If so do you also find it helpful?