The nephrolithiasis (or popularly "kidney stones") is a nephropathy that causes formation of stones or clusters of crystalline type within the urinary tract, which can move from the renal calyx which is described as the structure that carries out the transport of newly formed urine towards the renal pelvis (anatomical part that joins the kidney with the ureters), to the urethra (conduit used to expel urine to the outside, that is, urination); renal lithiasis is common in sedentary patients, in men who ingest little amounts of water and in people who have prolonged exposure to the sun daily.
Some factors that favor or provide the most common kidney stone formation are, mainly, decreased urinary volume either due to fluid loss or little water intake, bacterial urinary infection, abnormally high concentration of components in the urine such as calcium, phosphorus, magnesium, among others; The alteration of urinary pH can also be mentioned, which can generate the formation of acidic or alkaline crystals, the presence of mucoproteins causes alteration of the walls that line the urinary tract and favor the formation of casts, among others.
There are two types of calculi, the sedimentary ones that are made up of several crystallization centers and a decreased retention of organic compounds, and concretionary that are a little more ordered since several laminations concentrated around a central nucleus are observed. Among the most found at the urine level can be mentioned:
- Oxalate stones: they are hard, porous stones, they have various morphological characteristics, some are umbilicated brown stones, others are grayish-white and spiculated concretions, they can also be brown and spiculate, among others; its formation is favored by an acid urinary pH.
- Phosphate stones: they are small, white and of a soft consistency, they have a rhomboid appearance, cerebroid, made up of gray concretions with a mucous texture and this type of stone is generated by having an alkaline urinary pH.
- Uric acid stones: these have an oval or flattened shape, a smooth surface of brown or reddish color, hard and formed by granules, their formation is favored in acidic pH, as are oxalate stones.
- Cystine stones: they are yellow, with a soft texture and a granular surface, they are only present in patients with cystinuria.
