The urine is red and the microscopic examination is not abnormal. This is not hematuria. Certain foods like beets and red peppers, red food with dyes can also cause red urine; certain drugs and their metabolites such as senna, rifampin and dalantin can also cause red urine. In addition, intravascular hemolysis, myocyte damage and other hemoglobinuria is also red, these are not true hematuria, check the urine for red blood cells can be identified. Does the presence of red blood cells in the urine mean that it is really hematuria? No. In addition, some forgers intentionally mix blood into the urine to cause faked hematuria, which cannot be considered true hematuria. After the above conditions are excluded, urine examination with ≥3 red blood cells/high magnification field or ≥8000 red blood cells/mL, or 12-hour urine sediment count exceeding 500,000, can be diagnosed as true hematuria. It is generally believed that the presence of true hematuria means that there are lesions in the kidney, ureter, bladder, prostate and urethra or due to the involvement of other systemic diseases in the urinary system, which should be taken seriously now. Does one true hematuria mean something? Not true. Transient hematuria can be caused by pollen, chemical or drug allergies. Transient hematuria can occur after strenuous exercise, even in the flesh, and can occasionally occur with viral infections (such as the flu) and is usually not significant. Only when the test is repeatedly performed for true hematuria should it be taken seriously and further tests should be performed. The etiology of hematuria in young, middle-aged, and elderly patients is not identical. In order of incidence, urinary tract infections, glomerulonephritis, and congenital urethral malformations are common in hematuria in adolescents. In middle-aged people, urinary tract infections, stones and bladder tumors were more common. among patients aged 40-60 years, bladder tumors, kidney or ureteral tumors were common in men and urinary tract infections, stones and bladder tumors in women. ＞In patients older than 60 years old, enlarged prostate, prostate cancer, and urinary tract infection are common in men, and bladder tumor and urinary tract infection in women. The general procedure in hospitals is to first identify where the hematuria is coming from and do a bitemporal microscopy to see the morphology of the red blood cells in the urine. If the morphology of red blood cells is strange, the size is obviously different, and the number of red blood cells in each milliliter of urine is more than 8,000, then it is due to glomerular disease and a kidney puncture should be done. If the morphology of red blood cells in urine is normal, then intravenous pyelogram, CT, ultrasound and cystoscopy should be performed. Through these tests, the vast majority of patients with hematuria can determine what kind of disease it is due to.