There are three broad categories: the wrinkles caused by sun, expression lines and wrinkles caused by aging.
Photo aging or premature aging of the skin by sunlight: ultraviolet B (UVB) damage the surface layers of the skin over the years, the skin is no longer able to repair the damage and they become permanent. The skin thins; the renewal of cells is disturbed and the pigment cells clump together to form spots. On the other hand, ultraviolet A (UVA) work deep in destroying the elastic fibers and decreasing collagen (supportive tissue of the skin), causing a loss of skin elasticity and wrinkle formation.
Facial expressions: for example, smile, frown or squint lead to the formation of wrinkles in youth, and disappear when the expression goes. After 30 years, these wrinkles tend to persist, and from the age of 40, they are growing.
Gravity: it is constantly on the skin and causes it to sag with age.
Aging: With age, the skin is less well irrigated by blood, so less well oxygenated, and the muscles take longer as firmly in place, the skin will be more likely to form wrinkles and relax.
You can use an anti wrinkle cream to reduce skin aging as having an aged skin affects you deeply and disturb your mental balance.