Water is vital to the skin, Why?
The body is about 70% water.  How is this relevant to what we consume on a daily basis? It is recommended you drink 1.5-2 litres of water a day – approximately 8 glasses. Within a matter of hours, your skin will feel softer and have a natural glow.
Blood is mostly water, and your muscles, lungs, and brain all contain a lot of water. Your body needs water to regulate body temperature and to provide the means for nutrients to travel to all your organs. Water also transports oxygen to your cells, removes waste, and protects your joints and organs.
Dehydration Signs
Water is lost through urination, respiration, and sweating. If you are very active, you lose more water than if you are sedentary. Diuretics such as caffeine pills and alcohol result in the need to drink more water because they trick your body into thinking you have more water than we need.
Symptoms of mild dehydration include chronic pains in joints and muscles, lower back pain, headaches and constipation. A strong odor to your urine, along with a yellow or amber color indicates that you may not be getting enough water. (Note that riboflavin, a B vitamin, will make your urine bright yellow.) Thirst is an obvious sign of dehydration, but in fact, you need water long before you feel thirsty.
A good estimate is to take your body weight in pounds and divide that number in half. That gives you the number of ounces of water per day that you need to drink. For example, if you weigh 160 pounds, you should drink at least 80 ounces of water per day. If you exercise you should drink another eight ounce glass of water for every 20 minutes you are active. If you drink alcohol, you should drink at least an equal amount of water. When you are traveling on an airplane, it is good to drink eight ounces of water for every hour you are on board the plane. Twenty percent of your water needs will come from the fruit and vegetables you eat and the rest of your needs should come from the plain water you drink.