There is a small lump on the side of the testicle, possible causes: first, testicular inflammation, such as had testicular inflammation or is suffering from testicular inflammation, can appear localized swelling, bumpy, or accompanied by hard nodules and so on. Acute stage pain is more obvious, swelling is more obvious, while the chronic stage may not have obvious swelling, pain, no self-conscious symptoms when touching, it is recommended to carry out ultrasound examination of testicles to further identify. Second, epididymal inflammatory nodules, when epididymitis or epididymal tuberculosis and other lesions have occurred, epididymal nodules can appear, when the nodules and testicles are closely adhered to the testicles, can not be distinguished. In the acute stage, there is swelling and pain, and in the chronic stage, there is no symptom. If it is caused by tuberculosis, the patient may have fever or night sweating, etc. Ultrasound examination of the scrotum and tuberculosis mycobacteria examination are needed to confirm the diagnosis. Thirdly, testicular tumor, there may be focal hard nodules, and the volume may gradually expand and diffuse to the whole testicle in the late stage, accompanied by local pain, it is recommended to carry out ultrasound examination of testicle and tumor index examination of testicle to further exclude.