According to the EAU (European Association of Urology) guidelines for male infertility (2012 edition), the causes of reduced male fertility include congenital or acquired genitourinary tract abnormalities, genitourinary tract infections, elevated scrotal temperature (e.g., varicocele), endocrine disorders, genetic disorders, and immune factors. However, 30% to 40% of patients have an unknown cause, i.e., idiopathic male infertility. The most common diseases that cause male infertility are: 1. Spermatogenic dysfunction Spermatogenic dysfunction is the most common type of male fertility decline, except for sperm production disorders caused by hypothalamic-pituitary disorders and male reproductive tract obstruction. The clinical manifestation of sperm dysfunction is mostly non-obstructive azoospermia and severe oligo-teratospermia. 2, genetic diseases Genetic diseases include chromosomal abnormalities, genetic defects and other unexplained genetic diseases. 3.Obstructive azoospermia Obstructive azoospermia (OA) refers to the absence of spermatozoa and spermatogenic cells detected in semen and post-ejaculatory urine due to bilateral vas deferens obstruction. Varicocele is a common male disease associated with ipsilateral testicular growth disorders, pain and discomfort, and can lead to infertility. The prevalence of this disease is 11.7% in adult men and 25.4% in those with abnormal semen analysis. 5. Cryptorchidism Cryptorchidism is the most common congenital disorder of the male genital organs and is most common in premature infants. 6. Idiopathic male infertility Except for idiopathic oligo-weak teratoid sperm syndrome, infertility without a clear cause is idiopathic infertility, and such patients account for at least 44% of male infertility patients. The WHO believes that male accessory gland infections (MAGIs) include urethritis, prostatitis, orchitis, and epididymitis. However, there are no data to suggest that these diseases have a negative impact on semen quality and male fertility, and the Guidelines emphasize that the relationship between urethritis and prostatitis and male infertility is not clear. 8. Ejaculation disorders Ejaculation disorders are an important but uncommon cause of male infertility and are classified as non-ejaculation, frigidity, delayed ejaculation, retrograde ejaculation, premature ejaculation, and painful ejaculation.