doctor urologist doctor of medical sciences professor of the department of urology, evdokimov moscow state medical universityirection in a multidisciplinary clinic. good morning. come out to us. hello. good morning pavelich. in general, i'm wondering where kidney stones come from? but there are primary stones, there are secondary stones, that is. uh, true urolithiasis is most often a metabolic disorder and there are secondary stones, that is, stones that form against the background of some other diseases, if we combine all these diseases into a single group, then, most likely, these will be diseases that are characterized by a violation of the outflow of urine; urine is a hypersaturated solution of some salts; stagnation of a hypersaturated solution. next, the theory of crystallization. these crystals fall out to form stones, but even further everything is just different for me stones. they are different, they are very different, and more than that, i will tell you that here, uh, more or less one color scheme, but in fact they are also red there are also black and depends on the chemical composition. what ar