I too always have blood in my urine - sometime a trace other times 1+, etc. It was a major concern several years ago so my doctor sent me to a urologist who ordered a kidney screening (had to clean my intestines out, have dye injected, pictures taken on a set schedule). The test results showed all was well - no stones, no masses, etc. My mom also has the same problem and my urologist told me after the test it can be genetic and he felt all was well - he simply labeled it idopathic. I continue to have blood in my urine and no one questions it now unless the RBC count is high or I'm showing signs of an infection.