The increase of internal pressure caused by the belt could also cause Varicoceles, mostly occurring in the left testicle. It's essentially spider veins but in the veins directly connected to testicular tissue. They prevent the testicle from cooling down because of the warm blood build up, and this can cause atrophy, pain, and infertility if left unchecked. Luckily, fixing this issue isn't difficult. It involves an out-patient procedure called a Varicocelectomy, performed by a Urologist. It's has a recovery time of a few weeks, but there's a solid 15% chance of a Hydrocele developing from the surgery, which is a fluid build up in the testicular lining where the surgery was performed, caused by improper re-absorption of the tied off veins. Keep this in mind.