If a patient has red blood cells in the urine it is a case of blood in the urine. Generally speaking, red blood cells flow into the urine through other parts of the body. The reasons for its high index are kidney damage, strenuous exercise, physical diseases, and tumors of the urinary system. 1, kidney damage. Blood enters the urine through the kidneys, and if the kidneys are inflamed or have been physically injured, this can lead to an increase in blood in the urine, causing the red blood cell index to rise. Patients should listen to the doctor’s advice for treatment as a result of kidney causes. 2. Strenuous exercise. This is usually a normal physiological phenomenon that does not require much attention and will disappear after the body has recovered. 3, other diseases of the body. Other diseases in the body can also cause the risk of urinary tract infection, once the bacteria infect the urinary tissues, causing it to inflammation, will also cause the red blood cell index in the urine test to rise. 4.Urological system tumor. Increased urinary red blood cells is a common clinical manifestation of malignant tumors of the urinary system, so patients who repeatedly check for increased urinary red blood cells, or even have carnal hematuria, should undergo further examination to rule out the possibility of urinary tract tumors. Because there are many reasons for the increase in red blood cell index, patients should not be too careless and must go to the hospital for examination if they are usually uncomfortable, so as not to delay their condition.