Blood in the urine means hematuria. Depending on the time of occurrence, hematuria is divided into initial hematuria, terminal hematuria and complete hematuria. Initial hematuria refers to hematuria at the beginning of the urination process, and the color of urine becomes clear later on, suggesting that the lesion may be located in the urethra and bladder neck. Terminal hematuria refers to normal urine at the beginning of urination and then blood in the urine at the end, which usually indicates that the lesion may be located at the bladder neck and bladder triangle. Complete hematuria means that the urine is red throughout the entire urination process, which usually indicates that the lesion is located in the bladder or the ureter above the bladder, or the kidney. When hematuria occurs, the cause needs to be further defined, most commonly urinary tract infection, urinary stones, and urinary tract tumors. In addition to hematuria, urinary tract infections are usually accompanied by frequent and urgent urination, and the presence of white blood cells and elevated bacterial counts are clarified by routine urine tests. If the inflammation is controlled by anti-inflammatory treatment, the hematuria can be relieved on its own. For urinary tract stones, the stones can be removed by examination because they can cause damage to the mucosa of the urinary tract. For patients with tumors, ultrasound and CT examinations may be required to clarify the location and size of the tumor and treat it accordingly.