<s>[INST] Hi, I am 25, male and quite healthy. But, for the last 15-20 days I am experiencing slight pain in my left testicle and have discovered something as a lump on it. It seems the lump is on the testicle itself and not on the skin. The pain persists throughout the day. These apart, I have not experienced anything unusual as far as the functions of my testicles are concerned but am rather afraid about the lump-like thing. Please help [/INST] Hi, dairy have gone through your question. I can understand your concern. You may have some infection like epididymis orchids or abscess formation or some testicular tumor.  First you should go for ultrasound study.  If needed go for fine needle aspiration cytology or biopsy. It will give you exact diagnosis. Then you should take treatment accordingly. Hope I have answered your question, if you have doubt then I will be happy to answer. Thanks for using Chat Doctor. Wish you a very good health. </s>