RT Book, Section A1 Smith, James F. A1 Schmidt, Bogdana A1 Walsh, Thomas J. A2 McAninch, Jack W. A2 Lue, Tom F. SR Print(0) ID 1171187223 T1 The Aging Male T2 Smith & Tanagho's General Urology, 19e YR 2020 FD 2020 PB McGraw Hill PP New York, NY SN 9781259834332 LK accesssurgery.mhmedical.com/content.aspx?aid=1171187223 RD 2024/03/28 AB The proportion of individuals older than 65 years is expected to rise significantly over the next 25 years. According to US census data, the number of Americans older than 65 years will rise to nearly 55 million in 2020 (16.3% of total), and nearly 87 million in 2050 (20.7% of total). Consequently, the healthcare system will likely experience a dramatic increase in age-related health problems, such as cancer, cerebrovascular and ischemic heart disease, and hypogonadism. A substantial body of literature supports the assertion that hormonal changes in the aging male can be associated with significant health problems. This chapter reviews the epidemiology of age-related hypogonadism; alterations in testis biology that occur with age; and the effects that these changes may have on semen quality, fertility, birth defects in offspring, and on the overall health of older men.