To put thing's simply, varicocele causes ED. Usually if the left testicle is effected ED is a common problem.
I have this problem myself and it's a complete nightmare. Varicocele can cause testicular atrophy, messed up adreanl/thyroid function, low testosterone and other problems too.
I would advise him to get a full hormone profile done.
In the next few months i am going to have a website live with more information on varicocele, testicular disorders and hormones/ED, etc.
What age is he and has he experienced testicular shrinkage?
i was diagnosed with a varicocele (both testicles) and i dont think i have ED, but my libido id lower and testicles smaller. my urologists does not believe me, however. he says they are in a "normal range" so i shouldnt concerned. but i am concerned b/c they are smaller to me, and he doesnt take me seriously! he finally got bloodwork done adn testosterone levels came back "normal". i havent seen the results myself, so i cant really say where i fall in that range. any suggestions? something i can say to my dr. to get the ball rolling to feeling like myself again?