How does our skin hydrate itself?

Skin hydration is a vital process for maintaining its health, elasticity, and appearance. Understanding how our skin hydrates helps us not only to better care for it but also to prevent various skin problems such as dryness, irritation, and premature aging. This article explores the internal and external mechanisms that contribute to skin hydration.

HOW OUR SKIN HYDRATES FROM WITHIN

The Internal Mechanisms of Skin Hydration

1. The Structure of the Skin

To understand how our skin hydrates, we can study the epidermis, which is composed of three main layers: the epidermis, the dermis, and the hypodermis.

- The epidermis : This is the outermost layer of skin, which plays a crucial role in moisture retention. The epidermis contains cells called keratinocytes, which produce keratin, a protein that helps protect and waterproof the skin.

- The dermis : This middle layer is rich in collagen and elastin, which give the skin its strength and elasticity. The dermis also contains sweat and sebaceous glands, which contribute to hydration by producing sweat and sebum.

- The hypodermis : This is the deepest layer, composed mainly of adipose tissue, which helps to insulate the body and cushion shocks.

2. The Hydrolipidic Film

The hydrolipidic film is a thin protective layer on the skin's surface, composed of sebum (produced by the sebaceous glands) and sweat. It plays a crucial role in protecting the skin against external aggressors and in retaining moisture. This film prevents excessive water evaporation and keeps the skin supple and hydrated.

3. Natural Moisture Factor (NMF)

NMF is a combination of various water-soluble compounds, such as amino acids, urea, lactic acid, and mineral salts, found in the stratum corneum (the outermost layer of the epidermis). These substances attract and retain water in the skin, helping to maintain optimal hydration.

HOW OUR SKIN IS HYDRATED FROM THE OUTSIDE

The External Mechanisms of Skin Hydration

1. Topical Hydration

Applying moisturizing products to the skin is one of the most common methods for maintaining hydration. Creams, lotions, and serums contain moisturizing ingredients such as:

- Humectants : Substances such as glycerin, hyaluronic acid, and urea attract water from the environment and from the deeper layers of the skin to the surface.

- Emollients : These substances, such as vegetable oils and butters, help to soften and smooth the skin by filling the gaps between dead cells.

- Occlusives : Ingredients such as vegetable waxes or beeswax create a protective barrier on the skin to prevent water loss through evaporation.

2. Internal Hydration

Drinking enough water is essential for maintaining overall skin hydration. Water helps transport essential nutrients to skin cells and flush out toxins. Proper internal hydration is crucial for supporting cellular function and keeping skin moisturized from within.

3. Environment and Lifestyle Habits

Environmental conditions and lifestyle habits have a significant impact on skin hydration:

- Humidity : A humid environment helps prevent transepidermal water loss. Using a humidifier in winter or in dry climates can help keep skin hydrated.

- Temperature : Extreme temperatures, whether hot or cold, can disrupt the skin barrier and cause dehydration.

- Skin care : Using gentle products and avoiding harsh cleansers preserves the hydrolipidic film and the skin barrier. Taking short, lukewarm showers rather than hot ones can also help maintain hydration.