Dehydration can affect every person of every age. Most of us drink water only when we feel thristy. But the key to a well hydrated skin is to drink water even before you are thirsty. In order to keep skin’s collagen intact, you must make sure that you consume enough water. If you are not sure whether your skin is dehydrated, begin by drinking more water than you ever did before. After one week, observe whether your skin’s condition improves. Most people will find that their skin takes on a rosy, youthful, healthy look. As a minimum, drink eight glasses of water a day and don't wait for your skin to get dehydrated. A dewy complexion brightens up your face and also allows your make-up to stick, giving it a smooth application rather than a cakey/patchy finish.