Definition: Kidney shrinkage also known as kidney atrophy means that the kidney is smaller than the average size. A normal adult kidney is usually 10–12 cm long, 3–5 cm wide, and 3 cm thick, and weighs 150–260 g. Kidney shrinkage or kidney atrophy may be due to low blood supply to the kidney, loss of nephrons, chronic infection , blockage of the kidney or may be...