In simple words, varicoceles are enlarged veins. These can occur in the scrotum too. It presents as swelling or an enlargement above the testicle but without any discolouration. This affects a group of veins in the scrotum called the pampiniform plexus. The function of these veins is to cool the blood before it travels to the testicles. If the testicles get too hot, the sperms in them can become damaged. Blood that is cooler than the body temperature helps keep the fertility intact. Varicoceles do not often cause discomfort or symptoms except for swelling but can cause fertility issues.