Skin changes with age for many reasons, including the natural aging process, sun exposure, gravity, poor diet, environmental pollutants, stress and even the position in which you sleep. As you age all of these factors affect the skin, changing it both internally and externally.
As muscle tone decreases, skin begins to sag. The epidermis, or outer layer, of the skin also begins to thin and the skin can change in color, becoming more pale or translucent-looking. Spots, like sun or liver spots, can develop in areas that have been damaged by sun exposure, and warts or skin tags may develop.
As collagen levels in the skin decrease, lines and wrinkles begin to form due to the loss of elasticity of the skin. This is what gives the skin a leathery appearance in some people. As you age, your skin also produces less sebum so that it cannot produce the moisture it needs to stay healthy. This leads to dryness and itchiness of the skin and also results in wrinkles and a leathery appearance.
Changes start taking place underneath the skin well before they become noticeable. As you age the layer of fat beneath the skin begins to diminish, the cartilage in your nose wears away, and bone loss around the mouth occurs. This can lead to a sunken look around the eyes and cheeks, a nose tip that droops and a puckered look around the mouth. It can also result in a lack of insulation, reducing the body's ability to keep itself warm. In addition, the subcutaneous fat layer is responsible for the absorption of some medications, and the loss of this layer can lead to a difference in the way those medications work.
Another change that may not be visually apparent is that the skin loses its ability to produce as much sweat to keep the body cool.
Years of exposure to the sun causes the elastin in the skin to break down, leading to sagging and stretching of the skin. The skin is also more susceptible to injury, bruising and tearing, and injuries to the skin can take longer to heal. These changes in the skin occur slowly over a long period of time, and the effects do not become apparent until later in life. Skin can repair itself to some extent through cellular renewal, but a lot of damage cannot be undone.