Getting your testosterone checked is useful to a degree but IMO shouldn't be taken as the final word. For example, here are some of the issues with getting your testosterone checked and basing everything off that one, solitary reading:
* Variation in serum levels. Influences include aging, obesity, thyroid dysfunction, diabetes, estrogens, and certain other diseases and drugs.
*What to measure? Sex-hormone binding globulin-bound testosterone accounts for 44% of the total but is unavailable to cells
and affected by multiple conditions. Albumin-bound testosterone accounts for about 50% of the total and is weakly bound. Corticosteroid binding globulin-bound testosterone accounts for about 4% and is weakly bound. Free testosterone represents only 2% to 3% of the total and this is the important part
*One size does not fit all. Serum testosterone concentrations can vary by more than three orders of magnitude, depending on age, health, and other factors. No test can accurately capture the variation.
*Test technology. Radioimmunoassays, immunoassays, and liquid chromatography-mass spectrometry employ different principles to assess testosterone levels, and all have limitations.
*Lack of standardization. Includes definitions, parameters assessed, and reporting; there is no mandatory quality-control program.
Currently there is a lack of consensus about the definition of "low" testosterone among endocrinologists, urologists, and clinical pathologists. Published ranges for normal are based primarily on measurements in older men and are not
designed to establish ranges in men with normal sexual and reproductive function. Normal ranges should be based on testosterone levels derived from a predefined health index population, which currently they are not.
Source reference: http://www.goldjournal.net/article/S0090-4295(13)01611-7/abstract