A mass inside the scrotum. If a varicocele is substantial enough, a mass similar to a "bag of worms" could possibly be visible above the testicle. A more compact varicocele could be far too modest to see but noticeable by touch. Highly developed diagnosis. Mayo Clinic doctors use in-depth imaging https://www.sgvascularctr.com/what-are-veins-and-why-should-i-know-about-them/