Urinary occult blood mainly refers to hemoglobinuria or myoglobinuria. Urinary red blood cells refer to the red blood cells in the blood that have entered the urine, which is often referred to as hematuria. If there are more red blood cells in the urine and less occult blood, this suggests hematuria, which is more common in various kinds of nephritis as well as urinary tract infections, urinary tract stones, urinary tract tumors, etc. The diagnosis should be further confirmed by ultrasound or CT examination of the urinary tract. If there are fewer or no red blood cells in the urine and the urine is positive for occult blood, it may be hemoglobinuria or myoglobinuria, which is more common as hemolysis and rhabdomyolysis. This can be combined with the medical history, such as whether the patient has been transfused with the wrong blood, or whether the patient has symptoms such as muscle pain or swelling, which can be used to confirm the cause of the positive urine occult blood.