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19001717 . Testosterone is a steroid hormone primarily produced in the testes in men and in smaller amounts in the ovaries and adrenal glands in women. It plays a vital role in male development and reproductive health and contributes to libido, bone density, fat distribution, and muscle mass in both sexes. However, its levels are significantly higher in men than in women.
. The test is typically ordered to evaluate a variety of conditions. For men, it may be used to diagnose issues such as erectile dysfunction, infertility, or low libido. It could also be ordered if there are symptoms of low testosterone levels like reduced muscle mass, hair loss, or osteoporosis. For women, the test could be used when there are symptoms suggestive of high testosterone levels, such as irregular menstrual cycles, increased body and facial hair, or acne. These symptoms could indicate conditions like polycystic ovary syndrome (PCOS).
. There are two measures associated with testosterone tests: total testosterone, which accounts for the overall level of testosterone in the blood (including both bound and free testosterone), and the Free Testosterone Index (FTI).
. Free Testosterone Index (fTI) is a calculated value that represents the proportion of free (biologically active) testosterone compared to the total testosterone, taking into account the binding of testosterone to proteins like Sex Hormone Binding Globulin (SHBG).
. Since only free testosterone is biologically active, FTI is used alongside total testosterone and SHBG levels to provide a more accurate assessment of testosterone activity.
