For those of you who have issues with drinking water: do you have moderate to severe appetite/gastrointestinal issues as well? I have severe chronic abdominal pain, nausea, and a serious lack of appetite. I also don't get thirsty a lot of the time and I have to be careful about how much of anything I put into my stomach, water included. It's important to remember that anything someone with an autonomic disorder puts into their stomach might cause issues depending on how severe their condition is because the digestive tract requires blood to work. If you have low blood volume then blood diverting to one specific part of the body is going to cause problems and symptoms. For me specifically my symptoms get much worse after I eat, especially my pain and near-syncope issues.