Most people know that smoking is bad for your health.

It can increase your risk of cancer, cause problems during pregnancy and make you more likely to suffer from a stroke or heart attack. But even before you experience any of these catastrophic health problems, smoking has already made its mark on you. You can see this impact every time you look in the mirror.

When you take a puff, you’re causing irreversible damage to your skin. This habit can cause early wrinkles, and it accelerates the overall aging of your skin. After only 10 years of smoking, it’s already possible to see the effects in the faces of young adults.

Smoking causes wrinkles by narrowing blood vessels in the outer layers of skin. This causes less blood flow and reduces the amount of oxygen and nutrients that can get to the skin.

Smoking damages important connective fibers like collagen and elastin, causing permanent wrinkles. This damage doesn’t take long to appear — studies have found that even smokers as young as 20 years old had facial wrinkling that doctors could see under a microscope. And if you smoke 10 or more cigarettes a day for at least 10 years, you’re more likely to develop deeply wrinkled, leathery skin and a yellowish complexion.

Even the little things you do when you puff can contribute to skin damage. When you purse your lips to inhale or squint to keep smoke out of your eyes, you add even more stress to your skin. These actions create crow’s feet around your eyes and deep lines on the sides of your mouth [source: Hoffman]. And the damage doesn’t stop at your face. A recent University of Michigan study found that smokers showed signs of accelerated aging below the neck and even on their inner arms.