What’s the short answer to the persistent question about the importance of drinking eight glasses of water each day? No, you don’t have to do it. There is no scientific proof that, for healthy people, drinking extra water has any health benefits. Scientific research has shown that drinking large amounts of water does not:
Make skin look healthier or wrinkle-free
Benefit kidney function
Clean out toxins
Make you feel more energetic
The human body is beautifully designed to let you know you need to drink long before you are at risk of becoming dehydrated. Drink when you are thirsty. If you are doing strenuous work in a hot environment, drink extra fluid to make up for what you lose through perspiration. Use the color of your urine as a guide. Your urine should be light yellow. If it looks like water, you are drinking more than you need. If it is dark yellow or orange, you need to drink more.
Your doctor may tell you to drink larger amounts of water if you have certain medical conditions such as kidney stones, a urinary tract infection or diarrhea.
What are signs of serious dehydration that requires treatment?
Extreme fussiness or sleepiness in infants and children;
irritability and confusion in adults
Very dry mouth, skin and mucous membranes
Little or no urination (any urine that is produced will be darker
Shriveled and dry skin that lacks elasticity and doesn't “bounce
back” when pinched into a fold
Any adult or child experiencing any of these symptoms should see a doctor.
Source: University of Michigan Health System