Hydration is important because the body consist mostly of water. Drinking fluids serves a range of purposes in our bodies, such as removing waste through urine; controlling blood pressure; and maintaining a healthy metabolism.
Symptoms of dehydration includes altered behavior such as severe anxiety, confusion, or not being able to stay awake , faintness that is not relieved by lying down; an inability to stand or walk; rapid breathing; a weak, rapid pulse and loss of consciousness.
Most of us do a pretty good job of getting adequate amounts of fluids as part of our everyday routines: coffee in the morning, soda or juice with lunch, a glass of water in the afternoon, and water with dinner. Coupled with the water that makes up our food, usually, this is sufficient.
So we know we need fluids, we know the eight 8-ounce rule isn't backed by science, and we know that we need to strike a balance between too much and too little intake. We also know that almost any fluid will add value to our bodies, but water gives you the maximum results.