In October 1967, Mr. Aisin Gioro Pu Yi, the last emperor of China, died due to terminal kidney cancer. In fact, as early as 1962, Pu Yi appeared hematuria. But he did not pay attention to it until 1964, because of the sudden aggravation of hematuria, he had to be admitted to the hospital, and was diagnosed with “kidney cancer” after examination. The cancer cells had already metastasized to other parts of the body and it was too late for treatment. I. Definition of Hematuria Hematuria is not a disease name, but a common and important clinical symptom. In normal people, there are no red blood cells in the urine in general or very small amounts of red blood cells appear occasionally in individual cases. If there is an abnormal increase in red blood cells in the urine it is called hematuria. If the urine contains blood >1ml/1000ml, then the urine is red or the color of washed flesh water, which is called visual hematuria; if the urine color is normal, only the microscopic detection of fresh urine sediment red cell count ≥3 /HP hematuria is called microscopic hematuria. Second, hematuria with symptoms can easily attract attention. There are many causes of hematuria, most of which are accompanied by clinical symptoms. For example, kidney stones, bladder stones, urinary tract infection, acute nephritis, etc. For example, if hematuria is accompanied by symptoms such as increased frequency of urination, urinary urgency and painful urination, most of them are urinary tract infections caused by bacteria; if hematuria is accompanied by severe paroxysmal back pain, kidney or ureteral stones should be considered; if hematuria is accompanied by symptoms such as severe urinary pain and interruption of urine flow, bladder stones should be considered; if hematuria is accompanied by swelling of the eyelids, face or whole body and symptoms of hypertension, most of them are suffering from acute nephritis. When hematuria is caused by the above-mentioned reasons, it is easy to attract patients’ attention because it is accompanied by some obvious symptoms, and they can often go to the hospital in time for consultation and treatment. The causes and dangers of painless hematuria There is a kind of hematuria, called “painless hematuria”, which can easily make patients paralyzed and careless. Since painless hematuria can disappear temporarily without any treatment and is intermittent and intermittent, patients often think that the disease is eliminated when the hematuria disappears. However, painless hematuria is often an early sign of some serious diseases and often a sign of urological tumors. According to statistics, kidney tumors account for 40% of painless hematuria, and bladder tumors account for almost half of it, up to about 46%. Most patients with kidney and bladder tumors occur in middle-aged and older people over 40 years old. Therefore, after people reach middle age, if intermittent and painless hematuria occurs, they should pay special attention to it and must find out the cause and be alert to the possibility of urinary tract tumors, and should never be ignored. The diagnosis can be mostly confirmed by urine cytology, ultrasound, intravenous pyelogram, CT and MRI, and cystoscopy. Although kidney and bladder tumors, etc. are the most common malignant tumors of the urinary system, the lesions are not on the surface of the body and it is difficult for patients to detect them early on their own if there are no symptoms. Thankfully, these urological tumors often present with intermittent, painless hematuria at an early stage, which provides an important alarm signal for early detection. In the case of urological tumors, the tumor does not disappear when the hematuria stops, and the tumor continues to grow. Therefore, painless hematuria should be treated with caution and should not be taken lightly. Until the exact cause of painless hematuria is found, the possibility of urological tumor cannot be easily excluded. We must be alert to painless hematuria in our life.