Hematuria refers to a change in the color of the urine with the naked eye, such as a washout or soy sauce, or a positive urine test for occult blood (BLD, RBC). Therefore, some patients seek medical attention because of visual hematuria, while others seek medical attention because of occult blood found in urine tests, and these patients do not have significant changes in urine color to the naked eye. There are many causes of hematuria, and in general, they can be roughly divided into infections, stones, tumors, urinary tract abnormalities, and nephritis. Carnal hematuria can often be given high priority and can easily cause patients to be nervous. In fact, whether it is carnal hematuria or positive occult blood, the diagnostic process in medicine is basically the same. After the occurrence of hematuria, the most important test is to do urine erythrocyte locus to initially determine whether the hematuria originates from the urinary tract or from the glomerulus (the glomerulus is the core component of the kidney, like a filter, and blood passes through the glomerulus to produce urine). If the urine red blood cell pattern is predominantly homogeneous (these red blood cells are similar in shape under the microscope), it suggests that the hematuria originates from the urinary tract, and its common causes include urinary tract infection, urinary tract stones, and urinary tract tumors. Therefore, it is important for these patients to undergo further examination with urological ultrasound. If the urine red blood cell pattern reveals a predominantly red blood cell polymorphism, it suggests that the hematuria originates from the glomerulus. This often indicates a glomerular lesion. In patients who present with microscopic hematuria, the tests that need to be done are determined by the patient’s condition. For example, if the patient is elderly, the possibility of vasculitis should be noted; if the microscopic hematuria is accompanied by significant urinary protein, a kidney puncture biopsy is often required for further examination; if there is only microscopic hematuria without urinary protein or trace urinary protein, a kidney biopsy is not required in most cases, and regular annual urine and kidney function checks are sufficient; if a family member has kidney disease, the hematuria should also be taken seriously. At present, it is considered that simple microscopic hematuria is fine for regular review. There is no medical treatment drug for simple microscopic hematuria, and many clinical experiences also found that patients with simple microscopic hematuria are mostly stable in the long term.