hard pop up vein

During a prolonged erection [approx. 2 hours]  ,I noticed a hard 2 centimeter vein pop out on the side of my penis just below the head . Is this normal because I don't think I have seen this before. Ejaculation normal, but vein is tender if rubbed. Vein is "hard" even when penis is relaxed. Not on any medication or drugs. Please advise.

[Stephen Liroff, MD]

It sounds as though you are describing an inflammation of a lymph channel. These run parallel to the flair of the head of you penis, not longitudinalyl The cause of this condition is not clear but these do resolve on their own. Give it a month or two. You do not have to limit your sexual activity. It should decrease in size and go away. If it does not, and especially if it is increasing in size, see a urologist.
S.A.Liroff, M.D