Hematuria usually means “blood in the urine”, the urine is blood-colored, flesh-washing water-like, strong tea-colored, sometimes almost completely like fresh blood, and there are blood clots mixed with it, clinically it is called visual hematuria, sometimes the hematuria is very slight and can only be seen under the microscope, we call it microscopic hematuria. There are various causes of hematuria, which may be caused by inflammation of the urinary tract system, stones, tumors, trauma, prostatic hyperplasia, etc. Most of them are benign diseases and can be relieved by medication after diagnosis by a doctor. However, hematuria is often a danger signal of malignant diseases such as bladder cancer, kidney cancer, renal pelvis cancer, ureteral cancer and other tumors in the urinary tract system, and older patients with hematuria should first rule out the possibility of tumors, especially “painless hematuria” without pain and other symptoms, recurrent hematuria even after drug treatment, or even The B-ultrasound of the urinary tract system should be performed routinely, and further examinations such as CT, MRI, cystoscopy, etc. should be done if necessary. To sum up: hematuria is not scary, what is scary is not paying attention to it.