Hello there. Thank you for your question. I can understand Your concern. See, normally one testicle is larger than the other and hence hangs a little lower than the other, it's normal phenomenon, it doesn't cause any problem because we are made that way. But since you are saying there is pain accompanying a dwelling, I would like to know if the swelling and pain increases when you lift certain weight? Do you suffer from constipation? Have you ever noticed any change in the swelling and pain while lying down? Consult a general surgeon to get your self evaluated for hernia. It fits in your criteria. Hernia is not cancer. And if it's not hernia, whatever you are suffering from will be found out on physical examination and it need not be cancerous. Don't be scared. Consult a general surgeon at the earliest. Best regards. Dr. Anil Kumar jain