A small bump on the testicle after being hit is mainly considered to be related to testicular bruising, testicular cyst and other causes. 1. Testicular bruising: after the testicle is hit, it can lead to localized bruising and the rapid formation of hematoma, which in turn appears as a small pimple-like bump. 2. Testicular cyst: After being hit, it can lead to localized inflammation. Without timely intervention, cysts may form and this symptom may appear. 3. Other causes: In addition to the above causes, the appearance of small bumps on the testicles may also be associated with other causes such as folliculitis, genital herpes, warts and so on. The appearance of such symptoms may also be caused by other factors. It is important to consult a doctor as soon as possible to confirm the diagnosis, and be treated accordingly, in order to strive for a speedy recovery.