Thyroid gland function and male reproductive health

Over the past few decades, thyroid hormones have been studied thoroughly for their relevance to male reproductive health. Hyperthyroidism and hypothyroidism affect testicular function and neuroendocrine regulation of reproductive functions, which can lead to decreased testosterone levels and poor sperm quality and compromise male fertility. Understanding these processes is more relevant than ever in view of the continuing decline in sperm count and quality that has been observed in humans over the past decades. The literature review presents a brief concept of the regulation of male reproductive function by thyroid hormones and a possible mechanism by which thyroid dysfunction affects testicular function.