What causes kidney stones?

No well known cause. Kidney stones are hard crystals made of minerals and acidic salt. If prone to have kidney stones, change your life style and dietary habits. Consume enough water for body hydration, limit products that contain oxalate such as, chocolate, black tea, soy cheese, sesame seeds, wheat bran, figs, and blueberry etc. Increase magnesium citrate like brown rice, bananas and avocados etc. Exercise regularly.
Nephrolithiasis. There are many different types of stones including calcium oxalate (mono & dihydrate), calcium phosphate, struvite, cystine, indinvir, matrix and uric acid stones, to name a few. Stones of all types are caused by a highly concentrated urine resulting in crystalization and subsequent enucleation. Complete stone risk analysis includes assessing stone composition, specific serum and urine studies.