This document discusses male infertility, including definitions, prevalence, causes, evaluation, and treatment. It begins by defining infertility, subfertility, fecundability, and fecundity. It then discusses the prevalence of male infertility and various potential causes including idiopathic factors, hypothalamic/pituitary disorders, primary gonadal disorders, and sperm transport disorders. The document provides details on evaluation of male infertility through history, physical exam, semen analysis, and various specialized tests. It concludes by outlining medical and surgical treatment options.