Kidney stone 16 mm x 6 mm means that the kidney stone has a longitudinal length of 16 mm and a transverse length of 6 mm, which belongs to a relatively large kidney stone. The size of kidney stones can be categorized into small, medium and large using 5 mm and 2 cm as the dividing line. Kidney stones with a maximum diameter of less than 5 mm are small and have little effect on the kidneys, and most stones of this size can be expelled from the body on their own, but they may cause renal colic when passing through the ureter. Kidney stones with a maximum diameter of 5 mm-2 cm are relatively large, usually cannot be expelled on their own, and may cause obstruction, which can be considered to be treated by extracorporeal impact lithotripsy. Kidney stones with a maximum diameter of more than 2 cm cannot be removed by extracorporeal lithotripsy or ureteroscopy, and it is usually recommended to go to a regular hospital for percutaneous nephrolithotripsy, in which the stone is broken and removed by a specialized doctor. Smaller kidney stones can usually be removed by increasing water intake and diet control. When kidney stones are large, such as 16 mm x 6 mm in size, consult your doctor for the most appropriate treatment strategy.