Flesh-washing watery urine is clinically known as carnal hematuria, which may be caused by urinary tract infection, urinary tract stones, urinary tract tumors and other diseases. 1. Urinary tract infection: pathogenic bacteria stimulate the urethral mucosa, can cause urinary frequency, urgency, urinary pain and other urinary stimulation symptoms, serious infection stimulation leads to increased permeability of submucosal blood vessel wall causing bleeding, resulting in the emergence of wash water hematuria. 2. Urinary stones: If there are stones in kidney and ureter, it may stimulate the local mucous membrane to bleed, at this time, the patient may also have the symptom of hematuria. 3. Urinary system tumor: early urinary system tumor usually has no obvious symptoms, if the tumor invades the surrounding normal tissues or the tumor itself breaks down and bleeds, then the symptom of hematuria may appear, and the urine is usually pink or deep red. If the urine is found to be like washing water, it is recommended that the patients go to the urology department in time for relevant examination, after clarifying the cause of the disease, actively cooperate with the doctor for treatment, so as to avoid delaying the condition.