Most skin experiences periods of dehydration— and at any age, whether it is dry or prone to oiliness. Dehydration results from the skin’s inability to maintain an optimal water level. All cellular functions (cellular growth, enzyme exchanges, absorption of nutrients, etc) occur in the presence of water in the skin. Properly hydrated skin will always be structurally superior to dehydrated skin. This is why the skin must be properly moisturized to help it cope with the passage of time, making it a crucial component for healthy functioning skin, at any age.