Blood in my urine on ua only symptom is lasting right back pain radiating down right leg knee is swollen and painful can a kidney infection cause this?

Blood in urine. There are many people (1-5%) who have microscopic amounts of blood in their urine yet have nothing wrong with them. So the presence of blood is not necessarily, or even likely, related to your knee pain. A kidney stone could cause blood in urine and flank pain or pelvic or urethral pain, but not knee pain. I think they are unrelated, not a kidney infection, and a doc needs to examine your knee.