Varicocele is an abnormal dilation, elongation and tortuosity of the trapezius plexus in the spermatic cord due to factors such as obstruction of venous blood return or venous valve insufficiency blood reflux. Due to physiological anatomical factors, it is commonly found on the left side. It is a common genitourinary disorder in men and the main cause of male infertility. Its incidence is about 10-15% in men in general, rising to 35%-40% in men with primary infertility and about 75%-80% in men with secondary infertility, which seriously endangers the physical and mental health of male friends, so men should be detected and treated early. Here we will learn about the causes of infertility caused by varicocele. The reason one: varicocele can cause the temperature in the scrotum to increase due to blood stagnation in the spermatic vein, and the testicular temperature can increase by 1℃-2℃, the temperature continues to increase for a long time can affect the testicles to produce sperm, leading to azoospermia and oligospermia; the epididymis is also not conducive to make sperm maturation. However, sperm production disorders mainly occur in the primary spermatocyte and sperm cell stages. Cause 2: Blood stagnation, increased pressure in the spermatic vein, and lack of oxygen and nutrients affect the removal of metabolites, thus affecting spermatogenesis and maturation. Cause 3: Blood reflux during left spermatic varicocele brings substances produced by adrenal glands and kidneys such as steroids, catecholamines, 5-hydroxytryptamine, prostaglandins, etc. 5-hydroxytryptamine is one of the toxins and has toxic effects on testes, prostaglandins reduce blood circulation to testes and increase epididymal contraction, which is detrimental to sperm maturation and affects sperm motility. Reason 4: Varicocele damages the interstitial cells of testes, reduces testosterone secretion, peripheral blood testosterone content also decreases, while blood oogenic hormone and interstitial cell stimulating hormone increase, endocrine disorder, so much so that it interferes with the occurrence and maturation of spermatozoa. If you experience a sensation of falling and swelling pain in the scrotum or testicles in your daily life, or if your condition worsens when standing or walking, or if your symptoms decrease or disappear when lying down, be careful of varicocele. Be sure to go to the hospital in time to do the relevant examination, and do not worry if you are diagnosed with varicocele, as long as you go to the regular hospital for treatment, it is possible to cure.