Varioceles is a cluster of enlarged veins in the testes that accounts for 40% (or more) of all fertility problems – with these numbers being even higher among men suffering with secondary infertility (meaning that they have naturally fathered at least one child without intervention).
When varioceles occurs, blood that has clotted in the testes can heat the area to over 98.6 degrees, which is at least 1-2 degrees higher than they should be. This can cause serious damage (or even kill) sperm!