7 Gross Things That Happen to Your Skin When You Sleep in Your Makeup

6. Premature Aging

“Gases and dirt particles, or particulate matter, from smog and pollution can accumulate on the skin and get into your pores, which leads to free radical damage — inflammation and chemistry changes that can damage existing collagen, your DNA, and, in some cases, lead to an increase in pigment production, causing sun spots, dark marks, and irregular tone,” says Zeichner. Washing your face before bed shuts off the particulate matter faucet, so to speak, stopping buildup before it can cause all that damage, which tends to present itself as fine lines, wrinkles, crepe-y skin, pigmentation, and prominent pores — all things that can make you look years older than you really are.