Blood in urine needs to be evaluated. If it is gross (seen by you), it is very important to rule out some conditions. A sonography
and other tests will help. If it is microscopic, and routine tests do not reveal much, often repeat urine tests will tell if it was a one time finding, or if it is significant to warrant further tests. Low RB cells also need to be evaluated (may be due to iron deficiency
or other causes). Consult a physician for this. take care.