Likely you have Varicocele, very common in men. Majority of the time this goes undiagnosed and usually doesn't cause any major problem. Please get yourself examined, Ultrasound Scan Scrotum will give all the answers.

hello it is inflamation of epididymis get a scrotal scan done comlete haemogram done consult surgeon and decide bye

Hello there. I can understand your concern. You need to get it checked out by a general surgeon in person. It could be varicocele. You shouldn't  lift weights. But better to get it checked out once. You can find best surgeons near you on practo app itself. Best regards. Dr. Anil Kumar Jain. Balaji clinic. Bangalore.