What you need to know about the skin and its functions

How much do you know about your skin? It may seem like a thin layer of tissue, but in reality, it is the body’s powerful armor, protecting us from diseases and infections. At the same time, it allows us to communicate with each other and express our emotions.

“Skin does not exist merely to protect or cover muscles, organs, and bones. It is an organ, and in fact the largest organ of the human body,” says Dr. Markos Michelakis, Dermatologist-Venereologist (Aesthetic Dermatology-Dermatosurgery). “First of all, it is the first line of defense against the outside world, which is full of irritants, allergens, bacteria, viruses, fungi, and all kinds of pathogens. Moreover, it contains specialized immune cells that recognize anything harmful to its surface or attempting to invade the body, triggering an alert so that internal defense mechanisms are mobilized to protect the organism.”

The skin also contributes to regulating body temperature, participates in the elimination of metabolic waste, functions as a sensory organ, and protects the body from harmful ultraviolet (UV) radiation from the sun. Therefore, “maintaining the barrier created by the skin between the body and the environment is vital for our survival,” emphasizes Dr. Michelakis.

Even though it is so important, there is much we do not know or realize about it. Dr. Michelakis shares some key facts:

1. The structure of the skin is extremely complex. In each square centimeter, there are almost 7.5 million skin cells, 250 sweat glands, and at least 400 nerve endings, according to the American Academy of Dermatology (AAD). There are also about eight blood vessels and nearly 24,000 melanocytes. Melanocytes secrete melanin, the natural pigment that protects the skin from UV rays and gives the skin its characteristic color.
2. The skin has many layers. While the three main layers are well known (from outermost to innermost: the epidermis, dermis, and subcutaneous or fatty tissue), the epidermis itself consists of 23 distinct layers, 18 of which are composed of dead skin cells. New cells are produced in the lower layers of the epidermis (just above the dermis) and gradually pushed upward as new underlying layers form.
3. The skin continuously renews its cells. The human body constantly produces new skin cells (called keratinocytes) and sheds old ones. On a daily basis, we shed 30,000 to 40,000 old skin cells, and nearly all epidermal cells are replaced every 28 days.
4. Many conditions can manifest in the skin. The most common skin condition is acne. It is estimated that 85% of people experience acne at some point in their lives. Most cases occur during adolescence, but many are reported for the first time in adults, even over the age of 40. Acne usually begins after age 11 in girls and after age 13 in boys. By age 15, nearly 40% of teenagers already have acne or acne scars requiring medical attention.
5. Dry skin in winter can be dangerous. It is estimated that at least three in ten people experience dry skin, especially during the colder months when environmental temperatures drop significantly and we live and work in heated spaces. Dry skin is essentially a damaged barrier, making it vulnerable to infections from bacteria, viruses, and fungi.
6. Many chronic diseases cause skin manifestations (symptoms). Examples include heart disease, diabetes, liver conditions, obesity, and nutritional deficiencies. Even hormonal fluctuations during menstruation, pregnancy, menopause, or conditions like polycystic ovary syndrome can cause skin or appendage symptoms (e.g., oiliness, acne, increased or decreased hair growth, etc.).
7. Using too many cosmetic products can damage the skin. The AAD warns that using multiple products, especially anti-aging ones, can irritate the skin. It is better to focus on the basics: a gentle cleanser, a sunscreen, and a moisturizer. Establish a skincare routine twice a day (morning and evening) and stick to it.
8. It is not necessary to bathe every day. Most people bathe daily out of habit, personal preference, to wake up in the morning, or to smell good, but this does not necessarily benefit their health. On the contrary, daily showers, especially with hot water and soap, can promote dry skin, as they remove not only impurities but also the skin’s protective sebum. Using antibacterial soaps can also remove the “good” bacteria on the skin, disrupting its natural flora and promoting the growth of pathogenic bacteria. A quick shower every other day, with a mild cleanser and focus on the underarms and groin, is sufficient for most people, provided they do not perform manual labor, get dirty at work, or sweat excessively.

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