Dehydration: Not a pretty sight

Every day, we lose an amount of water equal to about four percent of our total body weight. If we do not take in enough perspiring, urinating and defecating, warning signals will go off loud and clear.

Early on, when we have lost just a little water, equal to about one percent of our body weight, we feel thirsty. If we ignore the thirst, it gets more intense.

When water loss raises to about two percent of our weight, our appetite fades. Our circulation slows as water seeps out of blood cells and blood plasma. And we experience a sense of emotional discomfort, a perception that things are not r...