The red blood cells in urine are the red blood cells in human blood. Red blood cells enter the urine after mucosal rupture and blood vessel rupture, and are found through microscopic examination, suggesting an increased number of red blood cells in the urine. They often occur in diseases such as infections, stones, tumors or trauma of the urinary tract, which cause mucosal rupture resulting in mucosal leakage of blood red blood cells into the urine, and can appear as an increase in the number of red blood cells in the urine. They appear in urine in a variety of forms, from broken red blood cells if the red blood cells have been destroyed by the glomerulus to intact red blood cells if they have not passed through the glomerulus. The presence of red blood cells in urine indicates the presence of bleeding disorders. There are many diseases that cause bleeding, and urine can only detect bleeding, but cannot determine the exact cause and location of bleeding, so further auxiliary other tests are needed to determine the cause and location of bleeding and to treat the symptoms according to the specific cause in order to cure.