How Uric Acid Stones Are Formed

Uric acid stones are primarily caused by an excessive buildup of uric acid in the body. When there is too much uric acid in the urine, a condition known as hyperuricosuria develops, which significantly increases the risk of stone formation. One of the key indicators of this condition is a urine pH level consistently below 5.5, meaning the urine is overly acidic. In such an environment, uric acid is less soluble and more likely to crystallize, eventually forming stones.

Uric acid stones are a distinct type of kidney stone, and their prevalence varies by region. For example, in the Yantai-Weihai (Yanwei) area of China, uric acid stones account for as high as 28.5% of all urinary tract stone cases. This is significantly higher compared to other regions such as Nanjing, Northeast China, Yunnan, and Guangdong, where the rate typically ranges between 5% and 7%. This regional difference suggests a strong link between diet and the formation of uric acid stones.

In coastal areas like Yanwei, dietary habits may play a crucial role. Residents often consume high-purine foods such as shellfish, organ meats, and beer, all of which contribute to elevated uric acid levels. Excessive intake of these foods can not only lead to gout but also increase the likelihood of developing uric acid stones. Therefore, uric acid stones are relatively common in this region.

In summary, understanding the causes of uric acid stones—especially the role of diet and urine pH—is essential for prevention and treatment. Maintaining a balanced diet and monitoring urine acidity can significantly reduce the risk of stone formation. Those living in regions with higher prevalence should be particularly mindful of their uric acid intake and overall urinary health.