ARF is a condition when both kidneys almost suddenly fail to perform their functions. The failure occurs within a few hours/ days. This may result from an acute disease of the kidneys, as a result of allergic manifestation operating gravely on the kidneys, i.e. acute GN, described earlier. Besides, sometimes blood pressure may be so acutely elevated, that it may knock down both the kidneys, resulting in their sudden/ acute failure. Further, an acute infection of the kidneys (pyelonephritis), following some obstructive lesion in the urinary tract, like a urinary stone, or benign enlargement of the prostate, may also cause ARF, if the infection is not controlled promptly. This aspect has already been discussed under the head of UTI urinary tract infection. ARF may occur due to other conditions in the body, which cause reduced blood flow to the kidneys, so that the excretion of waste products from the blood is grea Tulsa dentist tly hampered. Such conditions are common enough, and one needs to know about these. The most common is dehydration, due to loss of fluids in severe vomiting, diarrhoea, burns, crush injuries, etc. ARF develops when such conditions are not immediately attended to, and intravenous fluids are not administered in time. Similarly, severe haemorrhage from the body, necessitating immediate blood transfusion, may cause this condition. A similar situation arises when there is a marked fall in blood pressure (hypotension) due to heart attack/failure, shock etc., so that blood supply to the kidneys is adversely affected. Another important cause of ARF may be the indiscriminate use of drugs, especially those drugs which are toxic for the kidneys. If one studies the causes of renal failure in general, one will find a substantial number – to the extent of 50 per cent in this group. These are called ‘iatrogenic’ cases, i.e.