The skin accounts for about 15 percent of your body weight, says Barry Goldman, MD, a New York-based private dermatologist affiliated with Cornell Medical Center.
It also serves multiple purposes.
“It’s part of a team of organs that work together,” Goldman says.
“You can’t view the skin as simply something that wraps or covers up the body,” says Kemunto Mokaya (“Dr. Kemmy”), MD, a board certified dermatologist and author of “Live and Look Younger.” “It’s an important and essential organ system that’s complex and has many roles.”
The skin is a superhero organ for its ability to:
- provide immunity
- cover and protect internal body parts and functions
- release sweat
- synthesize vitamin D
- make melanin
- allow us to differentiate between textures, temperatures, and more via touch
Protects us from invaders
The top layer of the skin, or the epidermis, is the front line — literally — when it comes to defending our bodies against harmful external forces, like viruses.
“Intact skin can prevent pathogens from gaining a foothold,” says Goldman. “A disrupted skin barrier allows bacteria and viruses to penetrate deeper into the skin and cause infection.”
But even if pathogens penetrate the skin, this superhero organ will keep on fighting.
According to a 2020 review, skin cells team up and organize immune signals to help the body protect against and attack pathogens.
“White blood cells from the body constantly circulate through the skin, conducting immune surveillance,” Goldman says.
The skin also contains epidermal keratinocytesTrusted Source, cells that create proteins and peptides with antibacterial, antifungal, and antiviral properties
The sebaceous glands also secrete oil that adds another layer of protection against foreign substances. As a bonus, it keeps the skin soft.
Sheaths the muscles, bones, internal organs and nervous system
The skin’s protective properties don’t end with immunity.
Goldman says that the third layer of skin, the hypodermis or subcutis, is composed of fat that serves as a natural shock absorber.
If the body experiences trauma, such as a fall or car crash, this fat is essentially a thick cushion that stifles the blow and keeps our internal body safe.
Sweat isn’t simply a sign of a workout well done.
“Sweat helps to cool the skin and prevent the body from overheating,” Mokaya says.
Sweating occurs through two types of glandsTrusted Source. Eccrine glands cover most of the body and open onto the skin’s surface. Apocrine glands open into the hair follicle and can be found on the scalp, armpits, and groin.
Whether the body can “sweat out toxins” is a topic of debate.
A 2016 studyTrusted Source suggested heavy metal levels were lower in individuals who regularly exercised.
A 2011 studyTrusted Source indicated sweat was a potential way to remove Bisphenol A (BPA), a chemical frequently found in plastics.
Still, a 2019 reviewTrusted Source called for more well-controlled studies to clarify whether sweat plays a meaningful role in eliminating toxins in the body.
Synthesizes vitamin D
When the skin is exposed to the sun, it produces vitamin D, says Mokaya. Vitamin D serves multiple purposes in the body.
A 2015 reviewTrusted Source indicated it might help with:
- bone health
- protection against skin cancers
- immune function
- psoriasis management
- reduced risk and decreased severity of atopic dermatitis
Goldman notes that the epidermis contains melanin, a pigment that determines an individual’s skin color. The more melanin you have, the darker your skin tone will be.
Melanin does a lot more than determine your skin’s color. Goldman says it also protects against UV rays from the sun. These rays are responsible for:
- skin cancer
- premature aging
- reduced collagen production
- reduced skin elasticity
What would life be if you couldn’t pet your dog, cuddle a loved one, or feel the warmth of a fuzzy blanket? Thanks to the skin, we can feel the pain and pleasure of touch.
“The skin allows you to feel and recognize pain [and] pressure,” Mokaya says. “It deciphers textures and also detects temperatures such as heat and cold.”
The skin does this through tiny but powerful touch receptors, including:
- thermoreceptors that help determine temperature.
- nociceptors that let you know when something is painful, like a wound.