Anuria

Complete cessation of urine output. Anuria may be caused by a severe malfunction of the kidneys, but a more common cause is a complete blockage of urine flow, due to enlargement of the prostate gland (see prostate, enlarged), a bladder tumour, or a stone (see calculus, urinary tract). Failure of the kidneys to produce urine may be due to oxygen depletion as a result of reduced blood flow through the kidneys, as occurs in shock, or to severe kidney damage caused by a disease such as glomerulonephritis. Anuria requires urgent investigation. Treatment of the cause may restore urine production, but any delay can result in permanent kidney damage, leading to uraemia.