Your body needs water. Your skin needs water. Drink water.

It really is that important. 
While water alone can’t keep skin healthy — enough sleep, good nutrition, plus a good skincare regimen that includes proper cleansing, a moisturizer to prevent water loss (you’re seeing how important it is to prevent water loss, yes?) and strengthen the barrier layer…plus a daily sunscreen are needed, too — adequate hydration is crucial for your entire body’s proper functioning.
Among many, many other things, water flushes out toxins, keeps the membranous areas of our bodies moist, and brings nutrients to our cells.
You constantly lose water by breathing, sweating, and in urine, and to replenish, you need more than you may think: women need to be drinking about nine 8 oz. cups (a little over 2 liters); and men about thirteen 8 oz. cups (about 3 liters) of water a day.
Our body weight is about 60% water. Water…not juice or milk (which the body treats as food). This vital fluid is so important for our cells and our overall health, so make sure you’re drinking enough of it every day.
TIP: Not sure if you’re drinking enough water? Measure your intake by carrying around a water bottle that has an ounce or liter fill specified on it. For example, if your water bottle says that it takes 18oz, you know you need to refill it (and drink all of it) about 4 times throughout the day. Down a bottle after working out or at breakfast. Down another at lunch. Down a third in the afternoon. And down another at dinner.