What is the Origin of Sex Steroid Availability Assessment?

The term combines 'Sex Steroid,' referring to the gonadal and adrenal hormones, with 'Availability Assessment,' emphasizing the measurement of the functional, non-protein-bound portion. This crucial clinical focus developed in endocrinology to address the limitations of total hormone assays, which often fail to correlate with clinical symptoms when SHBG levels are pathologically high or low. The calculated free and bioavailable indices are the direct, most clinically relevant output of this sophisticated assessment.

What is the Mechanism of Sex Steroid Availability Assessment?

The mechanism is fundamentally predicated on the mass action law, where the concentration of the binding proteins

Sex Steroid Availability Assessment ∞ Area

Sex Steroid Availability Assessment

Meaning

Sex Steroid Availability Assessment is a precise clinical diagnostic approach that evaluates the fraction of circulating sex hormones, such as testosterone and estrogen, that is readily available to target tissues for biological action. This assessment goes beyond simple total hormone levels to include measurements of key binding proteins, notably Sex Hormone-Binding Globulin (SHBG) and albumin, to accurately calculate the free and bioavailable hormone indices. It provides a more precise clinical picture of hormonal status, particularly in conditions where binding protein levels are significantly altered, such as in obesity or with thyroid dysfunction.