Urinary calculi are stones that occur in the renal system and are one of the most common diseases in urology. The incidence is higher in the south than in the north. The age range of incidence is large, and can be seen in children, youth, prime age and old age. The ratio of male to female is 3:1-9:1, and middle-aged and young people account for 80%. The common symptoms are lumbar pain and hematuria, which mainly manifest in pain, soreness and discomfort in the lumbar region, etc. Some patients have stones that slip into the ureter and cause severe colic. Kidney stones may block the urinary tract and obstruct urine discharge, causing pain, hydronephrosis, and in severe cases, renal insufficiency. There are many causes of kidney stones, mainly systemic metabolic factors, local factors in the urinary tract, environmental and dietary factors, etc. Clinically, stones are usually classified into four major categories: calcium oxalate stones, mixed calcium phosphate and magnesium ammonium phosphate stones, uric acid stones and cystine stones. The human kidney can excrete various acids (hydrogen ions, lactic acid, glucuronic acid, beta-hydroxybutyric acid, oxalic acid, citric acid, etc.) and various salts contained in the urine in a dissolved state. However, if there is too little urine, crystals will form from these substances such as calcium oxalate, calcium phosphate, and uric acid, which are less soluble. The crystals continue to grow and eventually develop into clinically significant kidney stones. Kidney stones can be diagnosed by urine x-ray and ultrasound. CT is a more accurate non-invasive method to diagnose urinary stones and the treatment is clearer. If you have back pain and urine with the color of washed flesh, you should go to urology as soon as possible.