There are three main cases of testicular enlargement with pain on one side, and the treatment varies. The most common is acute testicular epididymitis, which is usually bacterial or mycoplasma or chlamydia infection, and treatment requires the use of broad-spectrum antibiotics for anti-infection treatment, such as cephalosporin antibiotics, azithromycin, levofloxacin, etc. For acute viral orchitis, the treatment can choose general antibiotics to prevent infection, mainly cooling and supportive treatment, and there is usually a natural course of disease. Testicular torsion is a scrotal emergency that requires vigilance. Generally, if testicular torsion is suspected, active scrotal exploration is recommended and timely torsional repositioning surgery is performed.