Testosterone deficiency: a common, unrecognized syndrome

Testosterone deficiency syndrome (TDS) refers to the clinical signs and symptoms that result from an abnormally low testosterone level. Men with ` classic' hypogonadism can have unequivocally low testosterone levels and typical symptoms and signs. By contrast, the age-related decline of testosterone levels can be responsible for ambiguous clinical pictures, which can potentially be misinterpreted as part of the aging process or depression. Nevertheless, this decline can have detrimental effects on quality of life and on the function of multiple organ systems. TDS is underdiagnosed -its overall prevalence varies from 6% to 9.5% in community-dwelling men aged 40 -70 years, and rises to 15 -30% in diabetic or obese men -and undertreated; less than 10% of men with TDS receive treatment. This Review highlights potential pitfalls in the diagnosis of both clinical and biochemical components of TDS.