Your skin is the largest organ of your body. It makes up about 16.6% of your total body weight. Skin is comprised of three layers, each with different functions.

The three layers of the skin are the epidermis, dermis, and subcutaneous layer (hypodermis). The epidermis is the outermost layer of your skin, the dermis is the middle layer, and the subcutaneous is the innermost layer.

The epidermis (outer layer), when healthy, acts as a physical barrier to bacteria and the sun. When the epidermal layer is healthy, your skin is able to fight off infections and retains its structural integrity. The epidermal layer of the eye is also very thin, which makes it easier to see blood pooling under the skin, which is one cause of dark circles under the eyes.

The dermis layer is comprised of the skin fibers elastin and collagen, which are responsible for retaining tone and firmness to the skin, and which provide the foundation on which new skin cells can grow. Thickness of the dermis’ collagen and elastin varies throughout the body. Our palms and soles of our feet have the greatest concentration of these fibers. The skin of our eyes has the least concentration of these fibers, making it more prone to sagging or looseness. The [tag-ice]dermis[/tag-ice] layer contains blood vessels, lymph vessels, hair follicles and sweat glands. It is also the layer which contains touch and pain receptors.

Excessive, unprotected sun exposure causes the dermis layer to breakdown, resulting in decreased elasticity and flexibility. Too much sun damage can cause your skin to age more rapidly, which is why wearing a protective sunscreen is vitally important.

The subcutaneous layer is mainly responsible for heat regulation of the body. It is made mostly of fat cells which act to keep us warm or cool us down, depending on the environment. These fat cells also cushion us (and our internal organs) against bumps and falls.

Your skin will change as you age. Skin cell production begins to slow in your 20’s, and collagen and elastin production slows down in your 30’s. If you are overweight, your subcutaneous layer will thicken, which can lead to stretching of the collagen and elastin, leaving cellulite and/or stretch marks visible on your skin.

Your skin needs to be treated well to keep you looking and feeling your best. You can promote good skin health by having good skin care habits, following a healthy diet, getting regular exercise, wearing sunscreen, and managing your stress.