The concept of body fluids in Korean medicine closely parallels modern dermatology's understanding of the skin moisture barrier, cellular water content, and metabolism. The stratum corneum, the outermost layer of the skin, consists of natural moisturizing factor and a lipid layer composed of ceramide, cholesterol, and fatty acid. Much like body fluids, natural moisturizing factor retains moisture within the skin. A deficiency in body fluids corresponds to a decrease in natural moisturizing factor or lower cellular water content, which weakens the skin barrier and increases transepidermal water loss. As a result, internal moisture evaporates quickly, leaving the surface dry and dull.
Furthermore, body fluids and blood are essential for producing and maintaining the collagen and elastin that determine skin elasticity. Fibroblasts can synthesize collagen and elastin effectively only when supplied with adequate hydration and nutrients from blood. When exhaustion of body fluids occurs, collagen and elastin synthesis declines and existing protein structures suffer damage more easily, leading to reduced elasticity and deeper wrinkles, much like a dried sponge losing its bounce.
In addition, chronic stress and irregular habits cause autonomic nervous system imbalance, impairing blood circulation while triggering a chronic inflammatory response and oxidative stress. These internal shifts accelerate the consumption of body fluids and induce DNA damage in skin cells, speeding up aging. Hormonal fluctuations also alter fluid levels; for example, xerosis cutis often worsens during the female climacteric because declining sex hormones contribute to the exhaustion of body fluids. Gut health plays a role as well, since gut dysbiosis elevates pro-inflammatory cytokines, weakening the skin barrier and accelerating the consumption of body fluids. Topical products alone have clear limits, as the skin ultimately reflects the internal condition of the body.
