As the amount of calcium intake decreases, the amount of oxalate available for absorption into the bloodstream increases; this oxalate is then excreted in greater amounts into the urine by the kidneys. In the urine, oxalate is a very strong promoter of calcium oxalate precipitation—about 15 times stronger than calcium. A 2004 study found that diets low in calcium are associated with a higher overall risk for kidney stone formation. For most individuals, other risk factors for kidney stones, such as high intakes of dietary oxalates and low fluid intake, play a greater role than calcium intake. Other electrolytes
Calcium is not the only electrolyte that influences the formation of kidney stones. For example, by increasing urinary calcium excretion, high dietary sodium may increase the risk of stone formation.Drinking fluoridated tap water may increase the risk of kidney stone formation by a similar mechanism, though further epidemiologic studies are warranted to determine whether fluoride in drinking water is associated with an increased incidence of kidney stones. High dietary intake of potassium appears to reduce the risk of stone formation because potassium promotes the urinary excretion of citrate, an inhibitor of calcium crystal formation.Kidney stones are more likely to develop, and to grow larger, if a person has low dietary magnesium. Magnesium inhibits stone formation. Animal protein
Diets in Western nations typically contain a large proportion of animal protein. Eating animal protein creates an acid load that increases urinary excretion of calcium and uric acid and reduced citrate.
It typically comes in waves lasting 20 to 60 minutes caused by peristaltic contractions of the ureter as it attempts to expel the stone.The embryological link between the urinary tract, the genital system, and the gastrointestinal tract is the basis of the radiation of pain to the gonads, as well as the nausea and vomiting that are also common in urolithiasis. Postrenal azotemia and hydronephrosis can be observed following the obstruction of urine flow through one or both ureters.Pain in the lower-left quadrant can sometimes be confused with diverticulitis because the sigmoid colon overlaps the ureter, and the exact location of the pain may be difficult to isolate due to the proximity of these two structures. Risk factors
Dehydration from low fluid intake is a major factor in stone formation. Individuals living in warm climates are at higher risk due to increased fluid loss. Obesity, immobility, and sedentary lifestyles are other leading risk factors.High dietary intake of animal protein, sodium, sugars including honey, refined sugars, fructose and high fructose corn syrup, and excessive consumption of fruit juices may increase the risk of kidney stone formation due to increased uric acid excretion and elevated urinary oxalate levels (whereas tea, coffee, wine and beer may decrease the risk).Kidney stones can result from an underlying metabolic condition, such as distal renal tubular acidosis, Dents disease, hyperparathyroidism, primary hyperoxaluria, or medullary sponge kidney.