What Is the Composition of Urine?

Of the forty-seven gallons of fluid filtered and processed by the nephrons daily, less than 1 percent actually becomes urine. Our urine is generally composed of things our body has no need for, such as some by-products of cell metabolism, and also excessive quantities of things we normally need such as water and electrolytes. About 95 percent of urine is water, while the remaining 5 percent is substances dissolved within.