" Kidney Stones Eating a plant-based diet to alkalinize your urine may also help prevent and treat kidney stones—those hard mineral deposits that can form in your kidneys when the concentration of certain stone-forming substances in your urine becomes so high they start to crystallize. Eventually, these crystals can grow into pebble-sized rocks that block the flow of urine, causing severe pain that tends to radiate from one side of the lower back toward the groin. Kidney stones can pass naturally (and often painfully), but some become so large that they have to be removed surgically. "

― Michael Greger , How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease