Controversies in the laboratory evaluation of hypogonadism: Androgen deficiency algorithm

Late onset hypogonadism is becoming a more relevant topic because of the aging population, and many older patients are questioning their physicians about treatment for symptoms of declining testosterone. Low testosterone is present in 6% to 12% of the US adult male population and has several known etiologies. The clinician needs to be able to recognize the signs and symptoms of hypogonadism and initiate an appropriate workup. Historically, assays measuring serum testosterone levels have been difficult to interpret for many reasons. This article aims to provide the physician with basic directions for interpreting testosterone test results and to create an algorithm for determining which patients are candidates for hormone replacement therapy.