“Normally, valves in these long spermatic veins reduce back force, but if the valves fail, this long column of blood from the kidney space all the way down to the testicle could cause dilation [widening] with the veins during the scrotum.” It may well vanish when the man lies down https://www.sgvascularctr.com/a-guide-to-varicocele-treatment-in-singapore/