The primary function of the kidneys is to filter out waste products from the blood and excrete them from the body in urine. During kidney failure, the organs don’t adequately remove the waste from the body. As a consequence, there’s a decrease in urine production. In some cases, people may develop an inability to urinate at all, signaling a critical portion of end-stage renal disease. Anyone experiencing a decrease in the amount of urine—especially those with a history of kidney disease, should seek medical assistance immediately.