Wrinkle is a ridge or crease of a surface. Usually refers to folds on fabric or clothes, or skin of a body, the folds are generally random and show no reason to repeat. Wrinkles are the thin, bent, sagging skin and that is particularly evident on the face, neck and hands. Wind, heat and chemicals and natural effects of aging cause a certain amount of wrinkling in everyone, but it is much worse in people who spend much time in the sun. Years of exposure to the sun cause "photo aging," which includes freckles, yellowing, roughness, visible blood vessels, and dark spots, like wrinkling.
In general, as a person ages, the sweat and oil glands of the skin become less numerous and smaller in size. This causes the skin to lose moisture and dry, and soon begins to fall in places where the collagen, the elastic fibers that support the skin, has weakened the most. The skin around the eyelids, jaw and neck is especially thin, and therefore more naturally prone to aging. In addition to sun exposure, smoking may contribute to the formation of wrinkles. Finally, it is believed that some wrinkling is predetermined genetically from one's parents.