If there is occult blood in the urine but normal urine red blood cells, it is possible that there is hemolysis or rhabdomyolysis. Urine occult blood and urine red blood cells are two different concepts. Urine red blood cells are detected when red blood cells from the blood enter the urine, while urine occult blood is detected mainly by hemoglobin, which is released when red blood cells rupture inside the red blood cells. The main thing that can cause red blood cell rupture is hemolysis, such as transfusion of the wrong blood type. Another thing that can cause positive urine occult blood is myoglobinuria, which is mainly caused by rhabdomyolysis. If the patient is allergic to high-protein foods such as silkworm pupae or suffers from muscle trauma, rhabdomyolysis can be caused. After rhabdomyolysis, a large amount of creatine kinase is released, which is filtered out by the kidneys and can be detected in the urine as positive for urine occult blood. In this case, in addition to the positive urine occult blood result, the patient will also have symptoms such as muscle pain, swelling, and red urine.