Bruise on the base of my penis

Hi. I

[H. Hunter Handsfield, M.D.]

If it looks like a bruise, that's probably what it is.  Whether from masturbation or something else I can't say.  We all get bruises from time to time (arms, hands, legs, etc) from trivial trauma we don't remember.  Probably the penis too.  If the bruise persists abnormally long or ohters start appearing, see a health care provider.  Otherwise forget it.

Good luck--  HHH, MD