Blood in the urine is often washed as a sign of urinary infection or kidney stones. And if it is not visible, it is not even considered.
In the kidney cancer, microscopic hematuria (Blood in the urine) can happen, which is not always observed by the naked eye. It can only manifest during the usual urine test. Sometimes the bleeding occurs periodically, so one day it is there, and in the next he went, which makes it easier to ignore. According to the US Cancer Society, it is one of the most common but not noticed early signs.