Left testicular pain may be caused by the disease of testicle itself, or it may be caused by neighboring organs. 1. Diseases of the testicle itself: for example, left testicular inflammation, epididymitis, testicular cyst, testicular tumor. Factors such as night may cause the symptoms of left testicular pain. 2. Diseases of neighboring organs: for example, prostatitis, seminal vesiculitis, varicocele, hernia and other reasons, may also lead to the symptoms of left testicular pain. In addition, inflammation or allergy of the scrotal skin, as well as nerve damage, can also cause the feeling of left testicular pain. When left testicular pain occurs, you need to go to the hospital in time for examination, to clarify the cause of the disease, and follow the doctor’s instructions to take appropriate treatment measures.