vein on front of testis

[pov]

Hello, I found some thin and long structure like vein on my left testicle. It starts in bottom and goes about 2/3 of testis to top (on front side). No pain or other discomfort. It is normal? Thanks for your opinion.

[dadmo]

What you have found is probably a Varicocele:

This is a complex of dilated veins which surround the testicle, usually on the left side. Varicoceles occurs in approximately 15% of normal males and are usually not important clinically, unless they are associated with infertility. A varicocele feels like a "bag of worms" surrounding the testicle, and may be accompanied by a constant pulling, dragging, or dull pain in the scrotum.

It shouldn't be dangerous but get it checked by a urologist.