The formation of stones in the kidneys or urinary tract is a fairly common disorder. The stones are formed from the chemicals usually found in the urine such as uric acid, phosphorous, calcium and oxalic acid. They may vary in consistency from grit, sand and gravel-like obstructions to the size of the bird’s eggs.

Stones may form and grow because the concentration of a particular substance in a urine exceeds its solubility. This disorder occurs more frequently in middle age, with men being afflicted more often than women.

The kidneys are two bean-shaped organs, lying below the waist on either side of the spinal column on the back wall of the abdomen. They are soft, reddish brown in colour, and, on an average, measure 10 cm. in length, 6 cm. in width and is 2.5 cm. thick at its centre. They are filtering plants for purifying the blood, removing water and salts from it which are passed into the bladder as urine.