The swelling and sinking of one side of the testicle may be caused by varicocele, testicular syringomyelia, chronic epididymitis and other diseases, patients should consult a doctor in time to clarify the cause of the disease. 1. Varicocele: abnormal dilatation and tortuosity of spermatic veins, patients will have swelling and pain on the diseased side of the testicle, this group of people should consult the doctor in time, and if necessary, surgery should be carried out. 2. Testicular syringomyelia: usually caused by inflammation or surgery and other factors, when there is too much fluid, there will be swelling and swelling of the testicle as well as tugging pain, and surgical treatment is the main treatment. 3. Chronic epididymitis: chronic inflammation of the epididymis caused by infection, obstruction and other factors, the patient will have testicular swelling and sinking, long-term recurring pain, which can be treated by anti-infection, local hot compresses or sitz baths. There are many reasons for the swelling and sinking of one side of testicle, which should be consulted in time for professional treatment.