Male fertility disorders: Pathology of varicocele, declining sperm quality and secondary sexual development

Varicocele is a common disease and has become an important cause of male infertility. Varicocele interferes with the "birth" of sperm, thus leading to male infertility. There are several reasons for this: (1) High temperature burns sperm: Varicocele causes the local temperature of the testis and epididymis to rise, affecting the spermatogenesis function of the testis.

(2) Endocrine disorders, interfering with hormone synthesis: Increased local temperature can also affect the level of endocrine hormones, reduce the biosynthesis of testosterone, and interfere with sperm production. (3) Blood stasis, damaging the testes: Blood stasis and small blood vessel embolism in the testes and epididymis lead to hypoxia and carbon dioxide accumulation in the tissues, damaging the seminiferous epithelium of the testes, and naturally reducing the number and quality of sperm.

(4) Metabolic products affect sperm production: Metabolic products of the adrenal glands and kidneys, such as catecholamines and prostaglandins, can reflux into the testes and epididymis through varicocele or communicating veins, affecting sperm production. Currently, the treatment of moderate to severe varicocele is still mainly surgical, primarily using high ligation of the internal spermatic vein.

Related surveys show that the sperm quality of Chinese men is deteriorating, declining at a rate of 1% per year. Compared to 30 or 40 years ago, the number of sperm per milliliter of semen has dropped from around 100 million to 20-40 million, a decrease of over 40%. Moreover, the more industrialized the region, the faster the decline in sperm quality.

In sperm donor samples, the number of rapidly motile sperm and sperm liquefaction kinetic energy showed a downward trend, while the number of microorganisms and pathogens increased. Beards are a hallmark of masculinity. Beard growth is a manifestation of male secondary sexual characteristics. Secondary sexual characteristics are stimulated by androgens secreted by the testes after a man enters puberty.

The amount and shape of facial hair vary greatly among men. It is related to ethnicity and family genetics, which is normal. If a man has no facial hair but his reproductive organs and secondary sexual characteristics are fully developed, it is not considered pathological. However, if puberty is delayed until age 18, or if puberty is not reached by then, it should be considered abnormal.

Pubic hair is also a secondary sexual characteristic. Its growth is a result of androgens stimulating pubic hair growth receptors. The absence of pubic hair in men may indicate developmental problems, especially if they are over seventeen or eighteen years old and still haven't grown pubic hair; in such cases, a thorough investigation is necessary. It's crucial to examine for any abnormalities in testicular size, penis size, facial hair, or Adam's apple.

This simple abnormality in body hair growth has no impact on overall physical or reproductive health; it is merely a physiological variation. Some men may find that their breasts have enlarged, and sometimes they can feel cord-like or nodular lumps, a condition medically known as gynecomastia.

Primary gynecomastia typically affects adolescent boys and older men, primarily due to a transient increase in endogenous estrogen or a decrease in androgens. Secondary gynecomastia is commonly seen in liver disease, testicular disease, tumors, and long-term use of certain medications. Clinically, gynecomastia is characterized by 60%–80% breast development, which may be bilateral and symmetrical or asymmetrical.

The lump is located concentrically with the nipple. If an off-center lump is found, other lesions should be considered; clinically, this type of lump is called "adenoma".