If a man has a large testicle with a small size, it is recommended to go to the hospital for testicular ultrasound examination to clarify the specific cause.1. If there is testicular inflammation, the testicle on the diseased side will appear to increase in size and be accompanied by obvious pain, redness and swelling of the scrotal skin and other inflammatory reactions. Testicular ultrasound examination can clarify the presence of inflammation and nodules, etc. 2, if there is a tumor of the testis, can also appear on the affected side of the testicular volume increased, accompanied by increased testicular density, palpation pain is not obvious, but the testicular hardness is higher. Testicular CT examination and testicular oncological index examination are needed to clarify whether there is testicular tumor or not.3. If suffering from testicular syringomyelia, scrotal enlargement in appearance can also occur. Generally there is no obvious pain, but the volume is too large, can produce a feeling of swelling, need to perform testicular ultrasound, to further identify.