首先要看这个dehydra到什么程度，轻度的时候身体会compensate，代谢应该是会加速
，重度的时候就应该是反过来了--这个和septic shock有点像？？下面这段可能比较全
面：
Symptoms of dehydration usually begin with thirst and progress to more
alarming manifestations as the need for water becomes more dire. The initial
signs and symptoms of mild dehydration in adults appear when the body has
lost about 2% of it's total fluid. These mild dehydration symptoms are often
(but not limited to):
* Thirst
* Loss of Appetite
* Dry Skin
* Skin Flushing
* Dark C
