Chronic kidney disease (CKD) occurs when the kidneys become damaged and can no longer adequately filter blood. The kidneys are responsible for filtering extra water and waste out of the blood to produce urine. When the kidneys don't function properly, waste can build up in the body, causing various symptoms and problems. Kidney disease can worsen over time and lead to kidney failure. Early diagnosis can help prevent further damage to the kidneys. Chronic kidney disease is a slow, progressive disease diagnosed in stages. Stages 1 and 2 indicate mild damage to the kidneys, while stages 3, 4, and 5 reflect more serious progression that affects prognosis and life expectancy. In this article, you will learn more about stages 3, 4, and 5 of CKD, life expectancy at each stage, and how to cope with the disease. FG Trade / Getty Images Chronic Kidney Disease Stages The stages of chronic kidney disease range from mild to severe. In the early s...