In infertility clinics, many men undergoing routine semen examinations often find low sperm count, poor quality, and low total volume. The previous standard of normal semen appears to be too demanding, and much less semen is truly qualified by its standards than in the past. In fact, it is not just that; the common factors of male infertility are quite tedious. Male infertility is divided into three main categories: infertility with normal sexual function, infertility with sexual dysfunction, and infertility caused by hereditary diseases. The main manifestations are as follows: 1. Semen abnormalities: low sperm count, reduced vitality and abnormal morphology. Factors affecting normal sperm production include: a congenital developmental abnormalities. Such as bilateral cryptorchidism caused by atrophy of the varicoceles, hindering sperm production; congenital testicular hypoplasia can not produce sperm; b systemic chronic wasting diseases, such as long-term malnutrition, chronic poisoning (smoking, alcoholism), mental overstrain, may affect sperm production; sexual life too often to reduce the amount of semen; c local causes: such as juvenile mumps concurrent with orchitis resulting in testicular atrophy; testicular tuberculosis so that testicular tissue The spermatozoa can sometimes be affected by varicose veins. d General bacterial infections, leading to prostatitis and vesiculitis. 2, sperm transport obstruction: tuberculosis of the epididymis and vas deferens can block the vas deferens and prevent the passage of sperm. Patients with impotence and premature ejaculation often cannot make sperm enter the vagina. 3, immune factors: sperm, sperm plasma in the body to produce antibodies against their own sperm can cause male infertility, the ejaculated sperm occurring their own agglutination and can not pass through the cervical mucus. 4, endocrine dysfunction: such as hypothyroidism, hyperadrenocorticism, hypopituitarism can cause infertility. 5, spermatogenic dysfunction: radiation, some metal elements (lead), some drugs (some anti-cancer drugs, hormonal drugs), alcohol, pesticides, fertilizers, some food (cottonseed oil), some bad habits (excessive smoking, alcohol abuse), mumps combined with testicular inflammation at a young age, and other factors can also affect the testicular spermatogenic epithelial function, causing a decrease in the number or quality of sperm, and even azoospermia. If the testicular function is affected, low testosterone levels will also lead to sexual dysfunction, impotence, etc. 6, sexual dysfunction: such as excessive masturbation leads to erectile dysfunction, etc. Not to be ignored there is also obesity, according to a survey in 2001, the national obesity rate of primary and secondary school students amounted to 5% to 7%, these fat children, many boys have abnormal development of the reproductive system, mainly short penis, testicles do not develop, the reason for most of the body estrogen significantly elevated, endocrine disorders caused by delayed gonadal development, androgen secretion reduced, perineal fat accumulation, penis hidden in the fat in the hidden type. Because infertility is often the result of a variety of factors affecting both men and women, the causes must be identified through a comprehensive examination of both men and women, which is the key to treating infertility.