Hello,
The symptoms are suggestive of varicocele. Varicocele is an abnormal enlargement of the vein that is in the scrotum draining the testicles. It causes dragging feeling or heaviness and visible veins in the testicles.Diagnosed by testicular ultrasound and treatment is by surgery(varicocelectomy). Varicocele can be worsened by any physical exertion during intercourse and heavy work. If the intercourse is too rough or masturbation too vigorous, then the pain of varicocele can worsen.
I sincerely hope that helps. Take care.
It seems like you have varicocele on your testicule. Does it hurt when you're working all day, standing up, running, lifting weights, etc.
then it goes away when you sit down?, check the back of your testicules to see if you have veins popping out.