The presence of red blood cells in urinalysis, known as microscopic hematuria, can be caused by the following three conditions: i. Chronic cystitis, which is usually combined with an increase in white blood cells in urine routine, can be treated by anti-infection. Second, urinary stones, which can also lead to microscopic hematuria, especially kidney stones or bladder stones can cause microscopic hematuria. Third, urological tumors can also cause submicroscopic hematuria, which is also an area that requires great attention, such as kidney cancer, ureteral tumors, bladder tumors or prostate cancer, all of which may cause submicroscopic hematuria. If submicroscopic hematuria is found on physical examination, further and more tests are needed to rule out related diseases.