The 18-year-old college student Li Lin, who was sleeping well at midnight, woke up from his sleep with a sudden sharp pain in his right testicle and right lower abdomen, a burst of nausea accompanied by a cold sweat, painful and cowering in bed. The students saw this and sent him to the emergency room of Tongji Hospital. Dr. Bian from the Department of Urology examined his abdomen and scrotum carefully and made a preliminary diagnosis of acute testicular torsion, and quickly sent him to the ultrasound room, where a Doppler ultrasound examination revealed that there was no blood flow to the right testicle. Later, after surgical incision of the scrotum, it was found that the right testicle was twisted 360 degrees along the longitudinal axis to the outside, and the testicle was swollen and more dark purple in color. The surgeon carefully reversed the testicle by 360 degrees, and the testicle regained blood supply and gradually turned red in color. To prevent re-rotation, the surgeon fixes both testicles at the bottom of the scrotum on each side. Testicular torsion is a urological emergency, the onset of which was first described by Dr. Delarsianve in 1840. It is not uncommon, but due to lack of medical knowledge, patients often delay for hours or even days, and the testes have undergone irreversible atrophy and necrosis due to prolonged ischemia, and although the swelling has subsided after a period of treatment, the testes have lost their spermatogenic function. The occurrence of testicular torsion has congenital anatomical factors as well as acquired causative factors. In the lateral direction of normal testes and epididymis, there is a part without sheath covering and directly attached to the surrounding tissues, which plays a fixed role. If the testis and epididymis are completely surrounded by the sheath and have a long submembrane, the testis is suspended in the sheath cavity like a pendulum, and torsion can easily occur if other triggers are encountered. These triggers are various, such as vagus N excitement during sleep and contraction of the levator muscle with penile erection, which can cause testicular torsion, sexual intercourse and masturbation, and various strong exercises that increase abdominal pressure, which can also induce testicular torsion. Testicular torsion can occur from infancy or even fetus to old age, some infants have had one testicular necrosis after birth, 65% occur in adolescents, with peak incidence at 14 years old and 40% occurring at night. Li Lin also had a small episode before he went to sleep: his testicle was kicked by someone during a fight with his classmates. The consultation provided a fog over the disease, and inexperienced physicians may assume that trauma is the cause, when in fact minor crushing and trauma is also a potential trigger. Urologists are not usually misdiagnosed because of their extensive knowledge, but patients are often mistakenly referred to general surgery for acute abdominal conditions such as appendicitis. Of course, when an experienced surgeon examines the abdomen and there is insufficient evidence of appendicitis, he or she will check the patient’s testicles for problems. Patients seen in urology are also sometimes identified with urinary stones and testicular epididymitis. In delayed cases, there are really some cases that look like epididymitis or orchitis, and in this case, emission nuclear scan or Doppler ultrasound is the best help for the doctor. Once the testicular torsion is diagnosed, surgery should be performed immediately, and every second is very important for both the doctor and the patient, as time is “life”. For undetermined testicular inflammatory lesions, if testicular torsion is suspected to occur, it is also advisable to explore as early as possible, with a survival rate of 100% if the onset is within 6 hours.