Why do we have to drink water.
Humans need to drink water to survive. Your body is approximately 60 percent water and your lungs are nearly 90 percent water.
Each day, your body must replace 2.4 liters -- or about 2.5 quarts of water -- through ingested liquid and foods.
Your body uses water in many ways. Water cushions and lubricates joints; nourishes and protects the brain.