Red, swollen and painful scrotum in children is collectively referred to as scrotal urgency. It represents a variety of conditions, including infection, testicular adnexal torsion, testicular torsion, and others, and of course needs to be differentiated from conditions such as inguinal hernia that has become ingrown, scrotal skin allergy, and allergic purpura. Testicular torsion is one of the more critical of these conditions and usually requires emergency surgery within 6 to 8 hours of onset to preserve the testicle, otherwise testicular necrosis may be found. Fortunately, the incidence of testicular torsion is not very high, and roughly speaking, our hospital has treated about 40 cases of testicular torsion in the past decade. If the scrotum is red, swollen and painful, you should be alert to the possibility of testicular torsion. Ultrasound Doppler can observe the testicular blood flow, which is important for diagnosis. If necessary, surgical exploration should be performed to clarify the diagnosis.