What is the Origin of Skin Hydration Index?

This term originates from biophysical dermatology, providing a clinical, non-invasive method for assessing a critical aspect of skin physiology. It translates the subjective feeling of dryness into a quantifiable, actionable number.

What is the Mechanism of Skin Hydration Index?

The Skin Hydration Index is a direct reflection of the water-binding capacity of natural moisturizing factors within the keratinocytes and the efficiency of the epidermal lipid barrier in preventing transepidermal water loss. Hormonal factors, notably estrogen, can enhance the production of hyaluronic acid and aquaporins, thereby increasing the skin's internal hydration reserves. Clinical interventions aim to optimize this index for maximal dermal turgor and resilience.

Skin Hydration Index ∞ Area

Skin Hydration Index

Meaning

A standardized, objective measurement that quantifies the water content within the stratum corneum and underlying epidermal layers, reflecting the skin’s capacity for moisture retention. This index is typically determined using a corneometer or similar device to assess electrical capacitance. A high, stable index is a key indicator of robust skin barrier function and overall dermal health.