First of all, a normal male should have two testicles, and they are located on the left and right sides of the scrotum, and there is a certain difference in the size of the testicles on the left and right sides, the testicles on both sides are not the same size, this is a physiological human difference, generally speaking, the testicles on the right side of the male will be slightly larger than the left side, calculated by the length, width and thickness of the testicles, the average right side is 3.38cmX2.37cmX1.78cm, the average left side is 3.30cmX2.27cmX1.71cm. As long as the testicles on both sides are within the normal range, it is a normal situation, so don’t worry too much. If the difference between the two sides of the testicles is particularly large, we should consider whether there is a lesion. First, some people due to congenital testicular dysplasia, the size of the testicles on both sides will always be different, the difference is also more obvious, mostly manifested as: one testicle is very small and soft, such as a toddler-type testicle, while the opposite testicle can have compensatory enlargement, larger than the average normal. Secondly, if one testicle is enlarged, accompanied by fever and local redness and pain, it may be epididymitis or orchitis, which requires timely urological examination, local ultrasound, and blood tests to further clarify the diagnosis and treatment. Third, in general, trauma can also cause the size of the testicles on both sides to be different, due to trauma-induced hematoma and bleeding in the testicles, thus causing testicular blood supply disorders, resulting in testicular atrophy, so the affected side is smaller than the opposite testicle. Fourthly, if one side of the scrotum has enlargement, it may also be mistaken for a swollen testicle, commonly seen in cases such as testicular syringomyelia or scrotal effusion, which requires prompt medical attention and, if necessary, may require surgical treatment. As long as the testicles are within the normal size range, there is no need to worry too much. If there is a clear enlargement or enlargement, it is recommended to seek medical examination in time.