Healthy kidneys clean blood by removing excess fluid, minerals, and wastes. They also make hormones that keep bones strong and blood healthy. But if the kidneys are damaged, they do not work properly. This is called kidney failure or renal failure or renal insufficiency. The two main forms are acute kidney injury, which is often reversible with adequate treatment and chronic kidney disease which is often not reversible.
Kidney failure is mainly determined by a decrease in glomerular filtration rate, which is the rate at which blood is filtered in the glomeruli of the kidney. The condition is detected by a decrease in or absence of urine production or determination of waste products (creatinine or urea) in the blood. Depending on the cause, hematuria (blood loss in the urine) and proteinuria (protein loss in the urine) may be noted.