Invisible blood in urine may indicate bladder cancer

One in 60 people over the age of 60 who had invisible blood in their urine -- identified by their GP testing their urine -- transpired to have bladder cancer, researchers report. The figure was around half of those who had visible blood in their urine -- the best known indicator of bladder cancer. However, it was still higher than figures for other potential symptoms of bladder cancer that warrant further investigation.