Sore testicles are usually caused by orchitis, prostatitis, varicocele, testicular tumor and so on. 1. Testicular inflammation: Due to sexual disorders, frequent masturbation and other reasons, which lead to bacterial infection and cause testicular inflammation, the symptoms of testicular soreness will appear. 2. Prostatitis: Due to the close location of prostate and testicles in men, when inflammation occurs in the prostate, the pain will be transmitted to the testicles through the nerves, which will lead to testicular soreness. 3. Varicocele: If men suffer from varicocele disease, the local blood flow will be hindered, which may lead to testicular soreness. It is also accompanied by the symptom of testicular swelling, which may cause male infertility in serious cases. 4. Testicular Tumor: If there is a testicular tumor, it will cause testicular soreness due to the gradual increase of tumor size. If the symptoms of testicular pain exist for a long time, you should go to the hospital for examination and treatment in time to avoid delaying the condition.