Kidney stones are a solid union of mineral salts that form in the kidneys. There are different types of stones, and each is linked to various causes. The most frequent causes of stone formation are diet, obesity, and certain diseases.
In general, stones occur when urine concentrates mineral salts such as calcium, oxalate, uric acid, or phosphate. The amount of urine is not enough for them to dissolve, and at the same time, the concentration of these salts is too high, and the urine may lack substances that prevent crystals from forming and adhering to each other. This combination of factors promotes the crystallization of mineral salts that grow to form stones.
- Calcium oxalate stones are found in most patients. Oxalate is produced daily by the liver but is also ingested through food. Bariatric surgery, certain digestive disorders (malabsorption), or metabolic disorders can facilitate the uncontrolled excretion of oxalate or calcium in the urine, leading to the formation of calcium oxalate complexes that crystallize.
- Struvite stones, also called infectious stones, can form in the case of a urinary infection. Bacterial activity causes a change in the urine's pH, which is not acidic enough to keep certain mineral salts like phosphate or ammonium dissolved. These stones grow very quickly and can become very large, occupying all the free space in the kidney without the patient noticing.
- Uric acid stones are linked to diets too rich in animal proteins or metabolic diseases such as diabetes, gout, or metabolic syndrome. People suffering from obesity are more prone to developing uric acid stones.
- Cystine stones are due to a hereditary disease called cystinuria, which causes the kidneys to excrete cystine, an amino acid, in such large quantities that it is not sufficiently eliminated with the urine flow and crystallizes. These stones are very recurrent.
Not drinking enough water every day, living in areas with a warmer and drier climate, or sweating a lot also represents a recurrent cause of kidney stone formation. Therefore, it is very important to have sufficient water intake every day, maintain a balanced diet, and, depending on the type of stone, take certain supplements that can help manage urinary pH and provide substances that inhibit the crystallization of mineral salts.
