I have had trace amounts of blood in my urine for many years (I'm 53). My doctors have always shrugged it off. I've always had to urinate on a fairly frequent basis, but haven't had any other problems until recently. I now have some soreness and something that I can only describe as a "buzzing sensation" in my bladder region.
What really concerned me (and it probably doesn't sound like much!) was the other night when I went to the bathroom (urinated only) and looked at the toilet seat and there was a small drop of bright red blood on it. When I wiped myself, there was nothing there and there hasn't been since. I had a hysterectomy four years ago, so it's not like I was on my period or anything.