Stones are due to an imbalance in the balance of colloid and crystal metabolism in the organism and are associated with infection, nutritional and metabolic disorders, urinary foreign bodies, urinary depression, and geographic and climatic factors. Men are more prone to this disorder than women. People over 30 years of age are more likely to develop this disease than younger people. It is relatively rare for children to develop the disease. Types and characteristics of kidney stones Depending on the composition of the stones, kidney stones can be divided into six categories: calcium oxalate stones, calcium phosphate stones, uric acid (urate) stones, ammonium magnesium phosphate stones, cystine stones and purine stones. Most stones can be a mixture of two or more components. The characteristics of various stones are as follows: (1) Calcium oxalate stones account for 80% to 84% of stones, often yellowish-brown or stone-bronze in color, with smooth (calcium oxalate monohydrate) or rough (calcium oxalate dihydrate) surfaces, with male onset as the most common, mostly with family history, and clearly visible on x-ray. There are often calcium oxalate crystals in the urine sediment. (2) Calcium phosphate stones: 6% to 9% of stones, white, rough surface, often antler-shaped, hard texture. They are often formed in alkaline urine. They are common in young and middle-aged men, with a family history, and are clearly visible on x-ray. (3) uric acid (urate) stones: 6%-10% of stones, smooth surface, often antler-shaped, yellow or brown, hard texture, blurred on x-ray or can not appear. They are more common in men, especially in gout patients, and usually have a family history. Uric acid crystals are visible in the urine sediment. (4) magnesium ammonium phosphate stones: accounting for 6-9% of the stones, stones yellow or dirty gray, dendritic or antler-shaped, soft texture. To women are more common, more patients with urinary tract infection, can not pass x-ray. The crystals of magnesium ammonium phosphate can be seen in the urine sediment. (5) Cystine stones: less than 2% of the stones, yellow or white, smooth surface, round, not easy to transmit x-ray, often formed in acidic urine. Cystine crystals can be seen in the urine sediment. (6) Xanthine stones: these stones are rarely seen, white or yellowish-brown in color, brittle in texture, cannot pass x-rays, and are usually formed in acidic urine.