Transepidermal water loss

Transepidermal water loss (TWL or TEWL) is a term associated with dermatology and its connected sciences. It is defined as the measurement of the quantity of water that passes from inside a body (animal or plant) through the epidermal layer (skin) to the surrounding atmosphere via diffusion and evaporation processes. TWL in mammals is also known as "insensible water loss" as it is a process over which organisms have little physiological control.