A micro haematura was noted 25 years ago during a routine medical. After a number of tests including a cystoscopy, a consultant nephrologist said that the blood was coming from my kidneys, that it was probably permanent and I may have had it for sometime. No treatment was neccessary. 

This morning I have had another cystoscopy, because another routine medical threw up the micro haematura again, and a very small red patch was noted just inside my bladder (enlarged, it looked loke a red ink blot).The Urologist said that it was not worth undertaking a biopsy and not to be overly concerned but he photographed it and said that he would do another cystoscopy in 6 weeks time. He was very reassuring but.........does anyone know, statistically, how often a red patch like this turns out to be a symptom of something serious?  I am a 74 year old male. Never smoked and never come into contact with any dangerous chemicals.