We’re all different, of course, and that means our skin can react in different ways depending on our skin type. Our facial skin in particular has ways of defending itself from these environmental nasties. It constantly generates natural oils which help to keep your skin hydrated and prevent these external aggressors from entering. However, as those with oily skin will know, if these oils stay too long, they can build up, trapping dirt and other debris. This leads to blocked pores, which result in blackheads, whiteheads and oily shine.
Alternatively, your skin may not produce enough of these oils. When dry skin is exposed to pollutants, it can result in sensitivity, blemishes, and flakiness, which makes hydration all the more important.