Variations in diagnostic criteria for male hypogonadism: is there a need for standardizing specialist society...

Male hypogonadism or testosterone deficiency is characterized by impaired testicular function resulting in reduced androgen production and altered spermatogenesis. The prevalence of late-onset hypogonadism is approximately 2.1% among men aged 40-79 years but it can reach 30% in specific populations. Despite its clinical impact and a market projected to reach $5.1 billion by 2030, there are discrepancies among specialist societies regarding nomenclature, diagnostic cutoffs, and classification. This narrative review discusses the guidance from: the European Association of Urology (EAU), American Urological Association (AUA), Endocrine Society (EnS), Society for Endocrinology (SfE), European Academy of Andrology (EAA), British Society for Sexual Medicine (BSSM), Italian Society of Andrology and Sexual Medicine (SIAMS), Italian Society of Endocrinology (SIE), and the International Society for Sexual Medicine (ISSM). Societies approach the condition differently in terms of nomenclature (Male Hypogonadism vs Testosterone Deficiency), classification, biochemical criteria, and follow-up protocols. Some organizations, including the EAU, SfE, SIAMS & SIE, favour "male hypogonadism," spotlighting diminished testicular function in both testosterone and sperm production. Others, like the AUA, BSSM, and ISSM, prefer "Testosterone Deficiency," emphasizing symptomatic low Testosterone levels. Classifications often distinguish primary from secondary causes, but several guidelines adopt categories such as functional or compensated hypogonadism. Finally, divergent diagnostic cutoffs for total and free testosterone create "gray zones" and differing follow-up recommendations-particularly around Prostatic Specific Antigen (PSA) and haematocrit (Hct)-underscore the need for standardization. As these inconsistencies may affect clinical practice and research, consensus-based, collaborative efforts from international expert panels are needed to establish universally accepted guidelines that address the current variability in male hypogonadism.