The production and maturation of sperm require the presence of an intact genetic blueprint in addition to a favorable environment. All the organs of male reproductive system must be fully formed and functional. In particular, the presence of adequate levels of the male hormone testosterone and a slightly decreased scrotal temperature are necessary.
Problems in any of these factors that govern male reproductive health will cause infertility. Based on how the reproductive system functions the infertility causes can be categorized into the following categories:
i. Impaired Sperm Production
ii. Impaired Sperm Function
iii. Impaired Sperm Delivery