My 1 testicle has internal swelling. When I touch there is a lump(small pea sized) connected with a nerve. There is a mild pain. Mild Pain only when I touch or my testicle shake when I walk or sit. Swelling is internal and swelling is not much ,i have little swelling in 1 testicle. After reading on Internet it seems the sperm containing nerve has swelling. And sometimes if I masturbate then there is painful ejaculation and very little or no semen comes out.