“Dr. Wang, I just had my first year of college, and when I took a shower for military training at school, I found that other boys’ testicles seemed to be bigger than mine, and mine were so small that I was embarrassed, will it affect my fertility?” 18-year-old Wang asked. “Dr. Wang, my right testicle has suddenly gotten bigger recently, and there is some pain, what’s wrong with it?” 38-year-old Liu asked. The testicles are an important reproductive organ for men, and the small “two” weight is responsible for the important mission of human reproduction, male friends from puberty should always be concerned about their testicles, so once you find your “balls” have something different must go to the male The two problems of Xiao Wang and Lao Liu are The two problems of Xiao Wang and Lao Liu are of great concern to many male friends, and in order to enable more male friends to understand testicular knowledge, the following questions are answered. The normal size of the testicles In order to know the size of the testicles, the first thing is to clarify the measurement method, commonly used measurement method for caliper measurement method: this method is not subject to the limitations of the conditions, the results are more accurate, but more time consuming. When measuring, the calipers are used to measure the long diameter, wide diameter and thick diameter of the testes respectively, and then the volume of the testes is calculated according to the formula. Testicular volume (ml) = long diameter (cm) × wide diameter (cm) × thick diameter (cm) × Л/6. Since 98% of the testicular volume is composed of the varicocele, the testicular volume is particularly relevant to the spermatogenic state of the testis. Adults with a testicular volume of less than 12 ml should be considered clinically to have a lower than normal spermatogenic function. Small testes can cause spermatogenic dysfunction of the testes and low or no sperm count, which may lead to loss of reproductive function. Physical examination and endocrine examination may reveal very low plasma testosterone levels, poorly developed male secondary sexual characteristics, such as scant beard, pubic hair and axillary hair, low and thin pronunciation or childish voice, and low libido and sexual function in most people. The main diseases that cause microcephaly are Cranfelt’s syndrome, congenital adrenal hyperplasia and some hereditary diseases. The testicles of normal people are not equal in size on both sides, according to statistics, the right side is slightly larger than the left side. As long as the size of both sides are within the normal range, it will not affect fertility. Some people, from childhood, have a small testicle, one side of the testicle is small and soft, while the opposite side of the compensatory growth, the difference is very obvious, this is congenital testicular dysplasia on one side. Trauma to one side of the testicle can also cause a large and small testicle, due to trauma causing bleeding and hematoma in the testicle, resulting in insufficient blood supply to the testicle, gradually atrophying and significantly smaller than the opposite side; some people suffer from mumps with orchitis as a child, and the virus destroys the epithelial cells of the varicocele in the testicle, causing one testicle to atrophy and a large and small testicle. If the testicles on both sides have been symmetrical in the past and suddenly appear to be significantly enlarged on one side, accompanied by fever and local pain, then it may be testicular inflammation or epididymitis. Most of the testicular deviations are caused by diseases, such as testicular syringomyelia, testicular tumor, epididymal tuberculosis, etc. These lesions, if not treated in time, can also cause low quality of sperm and semen and affect fertility. In conclusion, if the testicles on both sides are not very different and the size is within the normal range, it will not affect fertility. If one side is small and the other side is normal, the fertility may be low, but it is still possible to have children. When one side is too large or too small, it is necessary to consider whether there is a disease and should be promptly checked and treated in the urology department of the hospital.