Whats blood in urine and no pain?

Hematuria.: Blood in the urine, or hematuria, in the absence of infection, is abnormal and should be worked up. First, a urinary infection must be ruled out. Red cells are common in this setting. If there is no infection, further evaluation is needed to find the source. Work with your doctor to make sure you find a cause, or rule out the more worrisome ones.