Many men know they have a varicocele because they can feel the mass of dilated veins in the scrotum.
This feels like a sac of worms or spaghetti. These men have larger varicoceles. They have discomfort in that testicle or side of the scrotum. It can most clearly be felt when a man is standing and again, it will feel like a bag of spaghetti. A Doppler stethoscope will amplify the sound of blood moving past it.