Throughout a person’s lifetime, the skin is constantly changing. As people age, the skin begins to lose underlying fat (subcutaneous tissue) and the top two skin layers (dermis and epidermis) become thinner. Fine wrinkles increasingly appear, and the skin dries out and begins to lose elasticity.
Aging causes many changes in a person’s skin, ranging from wrinkles and sags to increased risk of developing noncancerous or cancerous growths and lesions. Environmental factors (e.g., sun exposure), genetic makeup and poor nutrition are among the agents that cause changes to the skin as a person ages.
The skin often appears thinner, paler and more translucent over time. “Laugh lines” may appear around the mouth, and crow’s feet may appear around the eyes. As gravity takes its toll, the eyelids begin to fall, jowls form and ears grow longer. Areas that are exposed to sun may develop brown patches known as age spots.
Intrinsic Aging
Intrinsic aging, also known as the natural aging process, is a continuous process that normally begins in our mid-20s. Within the skin, collagen production slows, and elastin, the substance that enables skin to snap back into place, has a bit less spring. Dead skin cells do not shed as quickly and turnover of new skin cells may decrease slightly. While these changes usually begin in our 20s, the signs of intrinsic aging are typically not visible for decades. The signs of intrinsic aging are:
1. Fine wrinkles
2. Thin and transparent skin
3. Loss of underlying fat, leading to hollowed cheeks and eye sockets as well as noticeable loss of firmness on the hands and neck
4. Bones shrink away from the skin due to bone loss, which causes sagging skin
5. Dry skin that may itch
6. Inability to sweat sufficiently to cool the skin
7. Graying hair that eventually turns white
8. Hair loss
9. Unwanted hair
10. Nail plate thins, the half moons disappear, and ridges develops
Extrinsic Aging
A number of extrinsic, or external, factors often act together with the normal aging process to prematurely age our skin. Most premature aging is caused by sun exposure. Other external factors that prematurely age our skin are repetitive facial expressions, gravity, sleeping positions, and smoking.
The Sun: Without protection from the sun’s rays, just a few minutes of exposure each day over the years can cause noticeable changes to the skin. Freckles, age spots, spider veins on the face, rough and leathery skin, fine wrinkles that disappear when stretched, loose skin, a blotchy complexion, actinic keratoses (thick wart-like, rough, reddish patches of skin), and skin cancer can all be traced to sun exposure.
“Photoaging” is the term dermatologists use to describe this type of aging caused by exposure to the sun’s rays. The amount of photoaging that develops depends on: 1) a person’s skin color and 2) their history of long-term or intense sun exposure. People with fair skin who have a history of sun exposure develop more signs of photoaging than those with dark skin. In the darkest skin, the signs of photoaging are usually limited to fine wrinkles and a mottled complexion.
Photoaging occurs over a period of years. With repeated exposure to the sun, the skin loses the ability to repair itself, and the damage accumulates. Scientific studies have shown that repeated ultraviolet (UV) exposure breaks down collagen and impairs the synthesis of new collagen. The sun also attacks our elastin. Sun-weakened skin ceases to spring back much earlier than skin protected from UV rays. Skin also becomes loose, wrinkled, and leathery much earlier with unprotected exposure to sunlight.
While it may seem that the signs of photoaging appear overnight, they actually lie invisible beneath the surface of the skin for years. UV photography enables us to see the damage accumulating beneath the surface of the skin years before the signs of photoaging appear. Most people are surprised by the amount of photoaging that the UV camera shows.
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