Your skin can do more than protect your organs—some amazing things (keep you cool) and others (burn, blemish, wrinkle) we’d rather live without.It Sweats: Our skin detoxifies our bodies. We sweat to cool ourselves down, and to increase blood flow (which releases toxins). Sweating is something you need to do regularly. It has cardiovascular benefits and a body-cleansing function.It Tans & Burns: The sun stimulates cells called melanocytes to produce and release a protective pigment: melanin. This process takes several days, long after you’ve left the beach.QUIZ: How Healthy is Your Skin?It WrinklesWrinkles don’t look good, whether they’re on your shirt or your skin. One major indicator of body aging is wrinkles—particularly the vertical lines around your lips and between your eyes.Each of these kinds stereotypically represents different things; cigarette smoking and inflammation in your blood vessels cause lip wrinkles. Vertical lines (furrows) between your eyes indicate stress.How do we get wrinkles? Since skin is attached to muscle, your skin creases when your muscles move. Over time this creates a well-worn groove. It’s like a stress fracture. The repetition of your skin bending over the muscle creates inflammation and the collagen gets squeezed together.Young skin can stretch and recoil over the muscle. Thinned, older skin loses this elasticity. Like an over-bent piece of cardboard, it eventually cracks.As we age, the connections between skin and underlying connective tissue stretch out. This causes skin to sag. Gravity pulls down, and the sagging adds to the wrinkle formation.MORE: Guide to Filling Wrinkles