A couple of months ago, my testicles started hurting, but they stopped, and my back is hurting now. I noticed that after I get out of the shower my left testicle has a lump on it, at first I thought it may be cancer , but I followed the lump back and it turns out its one of the veins in the back of my testicles. It only swells up after intercourse or a hot shower. I m planning to go to a urologist as soon as possible, but I wanted to know what this could be before I go. Thanks.