Wrinkles appear as we age, there are many factors that contribute to it. Young skin has allot of elastic to it, when the cells die and fall off they are replaced with younger cells. As we age, the cells are thinner which makes the skin thinner. This affects the moisture in the skin to decrease.

Another thing that effects wrinkles is that the body produces less collagen, this is the elastic in the skin. This is what causes the skin to produce wrinkles, and start to sag.

Sun Damage:

Exposure to excessive sunlight will age the skin and damage it. This will cause the skin to thin and cause the collagen to break down faster.

Smoking and Pollution:

Yes, it is true that smoking isn’t good for you or your skin. Smoking and Pollution will damage the skin at a faster rate, and will cause collagen to break down losing its elasticity.

Menopause:

It appears that lack of estrogen can decease collagen levels in the skin. While this hasn’t been 100% prove in humans, it has been experimented with animals.

All these factors together will cause the skin to lose it’s elastic ability, and cause wrinkles and sagging of the skin.