Testicular pain can be caused by the following three reasons. I. Epididymitis. Most of the pain is caused by bacterial retrograde infection forming inflammatory stimulation, also accompanied by swelling and tenderness of the epididymis as well as the testicles. Second, kidney stone radiating pain. Ureteral stones have radiating pain, along the direction of ureteral travel to reach the groin as well as the testicles, and testicular pain occurs. Testicular torsion. Mostly seen in young people, due to the relaxation of the levator muscle, the testicle will deviate from its original position to form torsion ischemia with severe pain, which can be judged by ultrasound.