Hi, I also have been experiencing excessive thirst- it started about 6 or 7 years ago. I was tested for diabetes and everything, always negative and was told that it was probably just in my head..so frustrating! Then almost 2 years ago, I was suddenly hit with a whole bunch of new symptoms. That is when I was diagnosed with autonomic dysfunction and POTS. I still suffer from extreme thirst at times which is such an uncomfortable feeling and keep thinking that it must be tied in here somewhere. I take a lot of salt tablets and can tolerate it pretty well (well, my nausea and vomiting pattern hasn't changed since I've started taking them or anything). I've had to do a lot of 24-hour urine studies and my docs have been concerned with the amount of urine, but they just attribute it to how much I drink...even though I really can't help how much I drink. When I'm thirsty and don't drink I have difficulty processing my thoughts and I wake up every morning feeling extremely dehydrated. But, I canrelate to most of your symptoms.