Epididymal tail nodule may be caused by acute epididymitis, epididymal cyst, epididymal tuberculosis and so on. 1. Acute epididymitis: acute epididymitis is related to hygiene and abnormal living habits, common hard lumps occurring bacterial infection caused by inflammation, can not receive timely and effective treatment, and eventually form the symptoms of epididymal caudal nodule. 2. Epididymal cyst: the fluid produced by the head of epididymis is not absorbed in time, and cystic lesions are formed locally, and the symptoms of caudal epididymal nodule will appear. 3. Epididymal tuberculosis: it is an inflammatory reaction of the epididymis caused by the infection of tuberculosis pathogenic bacteria, which will cause cauda epididymis nodule if not treated timely. There may be other reasons for the appearance of epididymal tuberculosis, patients should go to regular hospitals in time to find out the cause of the disease, under the guidance of the doctor for treatment.