<s>[INST] This is not a joke.  If I hold the head of my husband's penis in my hand and remain facing him, I can feel and see a rigid vein behind the head down the shaft.  When his penis is erect, it's even more noticeable.  He has no pain or discharge.  Should we be concerned?  What should we do? [/INST] Welcome to healthcare magic!It's normal. This vein is called dorsal vein of penis which is very prominent in all men.As you must be aware. Erection is result of increased blood supply to penis.So you need not worry about the same. It's absolutely normal. </s>