Drinking the proper amount of water aids in blood flow, nerve function, digestion, and virtually every function in the body, according to the University of Missouri. Adults should generally drink half their body weight in ounces of water per day, but this amount varies with activity and climate.
Dehydration leads to higher blood viscosity, according to Meridian Valley Lab. The thicker blood is, the harder the heart has to work to move it throughout the body and the higher the risk of heart disease and early death, says the American Heart Association. Adequate water also aids in regulating blood pressure.
Staying hydrated also promotes healthy digestion. Because water is a universal solvent, it is vital in breaking down and absorbing the nutrients from food, according to the European Hydration Institute. Too little water slows digestion and can lead to constipation or other digestive problems.
Nerve and muscle function also requires proper hydration, notes the University of New Mexico. Even a 2 percent loss in body weight worth of water can result in decreases in myostatic, or muscle nerve, conduction. To stay hydrated, it's best to drink water regularly rather than waiting for the feeling of thirst. Thirst is often a signal that a person is already dehydrated.