Is it normal for the testicles to be one big and one small?

Whether the testicles are larger or smaller is obviously normal cannot be generalized, and generally needs to be determined based on individual circumstances.

Testicles are male reproductive organs and are generally located in the scrotum. Generally, the left and right sizes are basically the same. There may be slight deviations, and they will be affected to varying degrees, such as dietary or environmental influences, which may lead to size differences. If there are no other uncomfortable symptoms, it is generally a normal physiological phenomenon.

If the testicles are obviously larger and smaller, or even accompanied by obvious swelling or pain, it is generally an abnormal phenomenon and may be caused by pathological factors, such as orchitis or epididymitis, and you need to go to a local regular hospital for relevant examinations and adjustments.