How the Skin Barrier Loses Water
How the Skin Barrier Loses Water — the process by which moisture escapes from the deeper layers of skin through the outermost barrier and evaporates from the surface, a phenomenon known as transepidermal water loss. When the barrier's lipids and cells are intact, this loss is minimal, but damage or dryness allows water to escape more readily.
Key points
- The outermost layer, the stratum corneum, acts like a brick-and-mortar wall where cells and lipids together limit water evaporation.
- Transepidermal water loss is the normal, continuous passage of water from inside the body out through the skin surface.
- A compromised barrier, from over-cleansing, harsh actives, low humidity, or irritation, increases water loss and leaves skin dry, tight, and sensitized.
- Key barrier lipids including ceramides, cholesterol, and fatty acids are essential for sealing in moisture, and their depletion raises water loss.
Frequently asked
What is transepidermal water loss?
It is the natural evaporation of water from inside the skin outward through the epidermis, occurring at all times. When the barrier is damaged, this loss increases and skin becomes dehydrated.
Why does my skin feel tight after cleansing?
Harsh or stripping cleansers can remove protective surface lipids, temporarily weakening the barrier and increasing water loss. Using a gentle cleanser and following with moisturizer helps limit this effect.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
