The tendon behind the testicle is painful, two diseases should be considered: First, acute orchitis and epididymitis, resulting in inflammation of the spermatic cord, in this case the spermatic cord has swelling and will have pain. Second, varicose veins of the spermatic cord, this pain is mainly aggravated when standing and after long time exercise, and it will be improved significantly by flat position and bed rest. It is suggested that a scrotal ultrasound examination should be done. The ultrasound reveals whether there is thickening of the spermatic veins and finds out whether there is enlargement of the testicles and epididymis. If it is caused by spermatorrhea, you should take oral broad-spectrum antibacterial agents. If it is caused by varicocele, you can take oral Mai Zhi Ling to achieve the effect of treatment, and the degree of varicocele is heavy, you need surgery.