Whether or not there is a problem with the testicles going up and down depends on the situation: 1. If there is a slight difference and the difference between up and down is not significant, the problem is not significant and is usually normal. With external stimulation and temperature changes, the scrotum contracts and stretches, which will lead to the testicles moving up and down. If the testicles on both sides do not move up and down much, it is a normal physiological phenomenon and does not need to be dealt with. 2. If there is a big difference between one up and one down, especially the one that is down, and there is a soft earthworm-like mass in the scrotum, the testicle that is down is likely to have symptoms of varicocele, and you need to go to the hospital to check the testicles, epididymis and spermatic vein ultrasound to confirm the diagnosis. If one goes up and down, the upper testicle can retract to the groin, which is a symptom of a wandering testicle. This symptom must be treated with surgery as soon as possible to fix the testicle in the scrotum, otherwise it will affect the male sexual function as well as fertility when it grows up.