Hematuria, commonly known as “blood in the urine” or “blood in the urine”, is a medical condition in which red blood cells are present in the urine, causing the urine to become red in color. Under normal circumstances, 0-3 red blood cells can be found in urine under a high-powered microscope, and when this is exceeded, the urine becomes microscopic hematuria, and when it can be seen with the naked eye, it becomes visual hematuria. There are many causes of hematuria, and every organ of the urinary system can bleed: kidneys, ureters, bladder, prostate, urethra, etc. And the most common causes are: infections, stones, tumors, trauma, etc. Infection: means there is inflammation, and some inflammation when due to inflammation of the kidneys, caused by poor filtration and reabsorption of the kidneys due to inflammation of the kidneys, this part of patients are best treated through nephrology consultation. In the clinic, a hematuria localization test can be performed to distinguish where the bleeding is. In other patients, if there is a previous history of tuberculosis, it is important to note whether the hematuria is caused by renal tuberculosis. If it is inflammation of the bladder, there are usually also symptoms such as frequent urination, urgency and painful urination at the same time. Stones: Stones in the urinary system can usually be diagnosed by X-ray or ultrasound. However, it is not true that all patients who have stones will have hematuria, it is just one possible cause of hematuria. Usually, stones in the ureter are more likely to cause urinary bleeding. Tumors: Patients over the age of 40 who have hematuria in the naked eye must be alert to the possibility of tumors. All tumors of the urinary system may cause hematuria, and it is a painless hematuria of the naked eye. Among them, bladder tumor has the highest incidence and is one of the most common causes of hematuria. Therefore, it is important for patients with painless carnal hematuria to seek medical consultation to find out the reason behind the hematuria. Other diseases of the urinary system, such as prostate cancer or inflammation, polycystic kidney, etc., may also complicate bleeding, and patients who have their own hematologic disorders, such as poor blood clotting and capillary disease, may also cause bleeding. Of course, we also have to pay attention to whether or not we have been taking some drugs that can easily cause bleeding recently, such as aspirin and phenolic drugs. In addition, if the patient has a history of pelvic radiotherapy or has had chemotherapy for bladder irrigation, it can also lead to radiotherapy cystitis, and hematuria can occur.