Any part of the urinary system is completely or partially obstructed, acutely or chronically, due to intraluminal or extraluminal causes. If the obstruction is not removed in time, it will eventually lead to hydronephrosis and impair renal function. In the upper urinary system, the pelvis and ureteral obstruction, hydronephrosis develops quickly, but often one side is damaged; in the lower urinary system, the bladder and urethra obstruction, because the bladder as a buffer, the kidney damage develops slowly, but often bilateral kidney damage. How to effectively prevent urinary tract obstruction? Pay attention to the diet and actively treat diseases about the urinary system. Medical history may suggest the etiology of the onset. Physical examination reveals distension of the lower abdomen with a turbid sound on percussion, sometimes the bottom of the bladder can reach the umbilical level. Examination of the penis, urethral orifice and urethra for hard, cord-like urethral scar tissue is indicated to exclude urethral strictures. Pay attention to a light diet, active exercise, regular medical checkups are better, and pay attention to a relaxed mood. Lower urinary tract infarction and infection must be eliminated. Such as surgical treatment of urethral strictures and other diseases, eradication of urinary tract infections, especially those bacteria that break down urea avoid bladder foreign bodies and reduce the occurrence of stones. To prevent the occurrence of upper urinary tract stones, urinary tract obstruction factors should be eliminated, such as for congenital urinary tract anomalies should be actively treated. If the narrowing of the prepuce and urethral orifice is detected early, it should be released in time. In case of trauma and inflammation, inflammation should be promptly controlled and urinary tract infection should be thoroughly treated to prevent the occurrence of urinary tract obstruction. For patients with urinary tract stones, prevention should be noted half-yearly review 1 increase in exercise, long-term bedridden people should often turn over. Drink a lot of water urolithiasis patients such as 50% increase in urine volume, the incidence of urinary stones will be reduced by 86%, especially before going to bed to drink more water to develop the habit of drinking water to maintain the daily urine volume of not less than 2000 ~ 2500ml. regulate diet, calcium oxalate stones patients should eat less spinach, reeds, tofu chocolate and other foods containing oxalic acid or calcium; calcium urate stones patients should avoid eating meat, crabs, spinach, animal offal such as liver, brain and kidney . Actively treat all kinds of infectious diseases. Long-term use of sulfonamide, acetazolamide and other drugs that can easily cause urinary crystals is not advisable.