Generally speaking, hematuria is called “visual hematuria”, which refers to the presence of more red blood cells in the urine, which can be seen with the naked eye as bright red or strong tea-colored. What is easily overlooked is “microscopic hematuria” in which red blood cells are found in the urine under a high-powered microscope. Hematuria can be helpful in the diagnosis of disease. In children, hematuria is most often seen in acute nephritis; in adolescents or middle-aged people, hematuria should be considered as non-specific bacterial infection of the urinary system, tuberculosis and stones; in women, if it occurs during the newlywed or childbearing period, it is mostly inflammation of the renal pelvis, bladder and urethra. If hematuria is accompanied by bladder irritation symptoms such as frequency, urgency and painful urination, urinary system infection should be considered; if it is accompanied by back pain, percussion pain in the kidney area or fever, it is more likely to be pyelonephritis; if only bladder irritation symptoms lack systemic infection symptoms, it is more likely to be cystitis; if hematuria occurs after severe colic, it is more likely to be kidney or ureteral stones. If the pain during urination, sudden interruption of urine flow or difficulty in urination are mostly bladder or urethral stones; if hematuria occurs after stool or sexual intercourse, it is often urethritis; if hematuria occurs when standing and disappears when lying down, it should be considered as renal prolapse; if hematuria occurs after strenuous exercise, it is post-exercise hematuria or kidney stone; if there is a longer period of difficulty in urination first and then hematuria, it should be considered as prostate disease or urinary tract infection. Among the myriad causes of hematuria, we should be alert to a type of painless hematuria because this type of hematuria is often a sign of malignant tumors of the urinary tract. The early stage of renal pelvic tumor will have painless hematuria with the naked eye throughout, which may be intermittent or persistent. Hematuria in renal tumors occurs mostly when the tumor invades the renal pelvis, mostly in the middle to late stages of the tumor, and the hematuria often occurs suddenly. When the tumor invades the nerve of perinephric tissues, only then the pain in the lower back is felt. The methods to diagnose renal tumor are intravenous or retrograde urography, CT examination, etc. The main symptom is intermittent spontaneous painless hematuria, i.e. hematuria is sometimes absent, sometimes more or less, and hematuria can last for several days or not appear for a longer period of time. Patients often mistakenly believe that the disease has been cured. The earlier the bladder tumor is detected, the better the treatment outcome. Prostate cancer is characterized by hematuria at the end of urination, accompanied by significant urinary frequency, urgency, painful urination, difficulty in urination, and urinary retention, etc. The enlarged prostate gland can be felt on anal finger examination, which can help in the diagnosis. In conclusion, painless hematuria is an early and important signal of urinary system, especially bladder tumor, which should not be ignored especially by middle-aged and elderly people. Once painless hematuria is found for the first time, you should go to the hospital for examination and confirmation of the diagnosis in time. For this reason, malignant tumors of the urinary tract cannot be easily ruled out in a patient with painless hematuria until the cause is found. Experts believe that anyone over 40 years of age should first consider malignant tumors of the urinary tract when painless intermittent hematuria occurs. In order to determine the site of occurrence of hematuria, the following examinations can be done: 1. repeatedly search for cancer cells in urine, if cancer cells are found in fresh urine, it will help to diagnose bladder cancer. 2. radiological examination, including abdominal plain film, static fat pyelogram and renal angiography, etc. 3. B-type ultrasound examination: it helps to diagnose polycystic kidney and kidney tumor. 4. radiological nuclear examination, commonly used kidney scan, is helpful to facilitate the diagnosis of kidney tumor. 5. 5.Cystoscopy can directly detect the site of bleeding and its nature. 6.Other tests: CT scan or MRI scan can be done if the source of hematuria cannot be determined or suspected to be from the kidney.