The Hair Loss Encyclopedia
water evaporates from the skin's surface, indicating barrier function
Transepidermal Water Loss (TEWL) refers to the process by which water passes from the inside of the body through the epidermis (the outermost layer of the skin) and evaporates into the environment. It is a key indicator of the skin's barrier function; higher TEWL values suggest a compromised skin barrier, which can lead to dryness, irritation, and conditions like eczema.