Unseen blood flow in the testicle is generally defined as no visible blood flow signal seen in the testicle when a testicular ultrasound is performed, and is most often seen with testicular torsion. Unseen blood flow in the testicle is most commonly associated with testicular torsion. When testicular torsion occurs, the blood vessels within the spermatic cord can rotate causing arterial blood to not enter the testicle and venous return to be blocked, resulting in acute ischemia of the testicle, which can lead to pain and swelling of the testicle. This situation requires prompt medical attention for testicular repositioning, otherwise there is a risk of ischemic necrosis of the testicular tissue. There may be other reasons for not seeing blood flow to the testicle. It is recommended to go to the urology department in time to ask the doctor to do further examination, and to be treated according to the specific cause of the disease.