According to the links affecting male fertility, male infertility can be divided into pre-testicular factors (endocrine etiology), testicular sexual factors (chromosomal abnormalities and other etiologies causing testicular damage) and post-testicular factors (sperm transport disorders and sperm dysfunction, etc.). Among them, endocrine factors, chromosomal abnormalities and other factors that cause testicular damage are the main causes of testicular spermatogenic disorders. 1, pre-testicular factors The pre-testicular factors are mainly endocrine factors, mainly hypothalamic lesions, pituitary lesions and fertility-related hormone abnormalities. Hypothalamic lesions include idiopathic hypogonadotropic hypogonadism, selective LH deficiency syndrome, selective FSH deficiency syndrome and other congenital syndromes; pituitary lesions include pituitary insufficiency, hyperprolactinemia and hemochromatosis; fertility-related hormone abnormalities include androgen abnormalities (excess androgens, lack of androgen synthesis and conversion of androgens into dihydrotestosterone, etc.). Androgen abnormalities (excessive androgens, lack of androgen synthesis, abnormal conversion of androgens into dihydrotestosterone and abnormal androgen receptors), excessive estrogen, abnormal thyroid hormones and excessive corticosteroids, etc. Testicular factors Testicular factors include chromosomal abnormalities and other factors that cause testicular damage Chromosomal abnormalities include klinefelter syndrome, XYY syndrome, xx male syndrome (sexual inversion syndrome), Noonan syndrome (male Turner syndrome), Y chromosome microdeletion and other chromosomal abnormalities. The main factors are varicocele, medical factors (such as drugs, radiotherapy and chemotherapy, etc.), environmental toxins and occupational exposure, cryptorchidism, testicular torsion, orchitis, only support cell syndrome and myotonic dystrophy, etc. Post-testicular factors The post-testicular factors include vas deferens obstruction, sperm dysfunction or motility disorders, immune infertility, sexual intercourse or ejaculatory dysfunction, etc. Obstruction of the vas deferens is one of the important causes of male infertility, and obstructive azoospermia is 7% -10% of male infertility patients, and there are mainly congenital obstructions of the vas deferens, such as cystic fibrosis (CF), Yong syndrome, idiopathic epididymis obstruction, and epididymis obstruction. epididymis obstruction, adult polycystic kidney disease (APKD) and ejaculatory duct blockage; acquired obstruction, such as reproductive system infection, vasectomy, surgery in the groin area, and Functional obstruction, such as nerve injury and certain drugs, sperm dysfunction or motility such as immotile cilia syndrome and maturation arrest, etc. Immune infertility, 2%-10% of infertility is related to immune factors. – 10% of infertility is related to immune factors, and antisperm antibody (AsAb) is an important cause of immune infertility. Common causes include testicular trauma, torsion, biopsy, infection or blockage of the vas deferens, after anastomosis surgery, etc. Sexual intercourse or ejaculatory dysfunction, decreased libido, and ED are common causes of infertility: diabetes, inflammation of the bladder urethra, abnormal bladder neck muscles, hypospadias, surgery or trauma that damages the nerves can also lead to non-ejaculation or retrograde ejaculation; poor sexual habits, such as too frequent intercourse, application of stimulants and lubricants, can also affect fertility.