In fact, men’s testicles are not perfectly uniform in size, and all have some variation in size. However, under normal circumstances, this difference can hardly be seen with the naked eye. If there is a very obvious testicle size difference, it is usually caused by chronic epididymitis, testicular trauma, orchitis and other factors. If a man suffers from chronic epididymitis, he will have a large and small testicle, mainly because epididymitis will cause the epididymis on one side to suddenly increase in size, so from the surface it will appear to be a large and small testicle. In general, epididymitis does not affect the sexual ability of men, but because the epididymis is affected by inflammation for a long time, it will gradually harden, resulting in painful ejaculation. If a man’s testicle is injured, it will also appear to be one big and one small, because trauma to one testicle will lead to edema inside the testicle, which will cause the testicle to slowly shrink after insufficient blood supply, so it will look one big and one small. The main factor for the testicles to become one big and one small is testicular inflammation. If the testicular inflammation is not treated in time, the testicles on the affected side will atrophy and naturally form one big and one small situation. If one of the testicles suddenly becomes bigger and there is pain, then the possibility of orchitis or testicular injury should be ruled out and you need to go to the hospital in time for examination and treatment.