The most common cause of fine lines and wrinkles is the natural aging process. This rate of aging is called intrinsic aging which is determined by your genetic makeup. As we age our skin gets thinner and loses elasticity which causes the skin to wrinkle and fold. As a result of intrinsic aging, fine lines and wrinkles can generally occur between the ages of 30 and 35. Although we can't help the progression of intrinsic aging, we do have control over extrinsic aging due to exposure to environmental conditions. Examples of extrinsic aging include:

Excessive Sun exposure

Too much sun exposure can lead to dry skin and the loss of collagen and elastin. As a result, skin begins to sag and form wrinkles and folds.

Sleeping Positions

The way we rest our head when we sleep can lead to sleep lines overtime. Consistently sleeping with your face against the pillow in the same position is what causes sleep wrinkles to develop. Women, who sleep on their sides the majority of the time, are likely to develop lines on their chin and cheeks. Men generally develop sleep lines on their forehead.

Smoking

The numerous chemicals in cigarettes cause biochemical changes in the body which can lead to premature aging. Nicotine, in particular, restricts proper blood circulation and consequently the body is unable to receive the proper amounts of oxygen and nutrients it needs to keep the body and skin healthy.

Facial expressions

Facial expressions are how we physically wear our emotions. Every time we make one of these expressions, whether it is smiling or frowning, our skin remembers that muscle contraction and thus tiny creases begin to form underneath the skin. When we are younger our skin has more elasticity and collagen making it easier to recover from these creases. But, as we age our skin begins to slowly lose its elasticity, making it harder to bounce back.

Stress

When we are stressed our body produces the hormone cortisol. Cortisol is an essential component to keeping the body healthy; however, in excessive amounts in can cause enormous damage. In instances when we are severely anxious and stressed, the body produces higher amounts of cortisol. If you are under a constant bout of stress, these elevated levels of cortisone can remain in the body for a long period of time, causing damage to bodily processes and affecting the appearance of the skin. Protecting ourselves from exposure to extrinsic aging factors is the best way to prevent premature aging.