8. Stress Out
It's not your imagination. Stress really does show in your skin.
"It's not well understood, but it's clear that stress makes many skin conditions worse," Dover says.
Stress can cause flare ups of psoriasis and rosacea as well as acne. It may also lower the skin's ability to keep out harmful irritants and infections. Plus, people who are wrapped up in their stress have less time to care for their skin properly.
9. Overdo It
Looking young and vibrant is highly prized. But the quest for it can have a price, especially if you trust your chemical peel to someone without an MD after his or her name.
"I think they should be done under the guidance of a doctor because they certainly can be very irritating, particularly to sensitive skin or people who have skin conditions," Stein says. In the wrong hands, a chemical peel could leave you with an infection or permanent scars.
You also don't want to overdo home microdermabrasion and peels. Instead of making you look younger, they'll leave your skin red and irritated. Let your dermatologist guide you if you are going to try at-home skin procedures.
When you gain a lot of weight, your skin has to stretch to accommodate your new girth. Lose the weight and you'll be left with flabby, saggy skin. If your skin isn't elastic enough to bounce back, it can be incredibly difficult to tighten it up.
11. Fall Short on Sleep
More than a quarter of Americans aren't getting the seven to nine hours of sleep we need nightly, and our skin (and bags under our eyes) show it.
"Your skin rejuvenates while you're sleeping," Dover says. He warns that a lack of sleep makes your face look "dull and listless" and can exaggerate the appearance of dark circles.
12. Ignore Warning Signs
A changing mole is one of the clearest signs of skin cancer. Spotting it early gives your doctor a chance to treat it before it has time to spread. But how will you ever know a mole is changing if you never look at your skin?
Check your skin from top to bottom, front to back in a full-length mirror once a month. "You're looking for changes in the size, shape, and color of moles or for new moles," Dover says. If you spot anything, or if you've got a personal or family history of skin cancer, ask your dermatologist to do a full exam as well.