The kidneys may fail due to a decrease in the blood supply, damage to blood vessels or filtering units (nephrons), or blockage of the urinary tract. Illnesses that affect the entire body, such as diabetes or high blood presesure, are the most common cause of kidney damage. Filtering problems may also be caused by illnesses that harm the kidneys directly (glomerulonephritis and polycystic disease).
Kidney damage can be temporary or permanent depending on what caused it. Kidneys have the capacity to heal themselves if the cause is temporary.
Problems with blood vessels
An illness can damage blood vessels inside the kidneys. As a result, the filtering units receive less blood, and pressure inside the kidneys cannot be controlled.
Problems with filtering units
Reduced blood supply or the wrong pressure can harm the filtering units. This makes them less able to remove wastes from the blood. As a result, the kidneys can’t maintain the proper balance of fluid and chemicals in the body. Waste products may be returned to the blood, or vital chemicals and proteins may be lost in the urine.
Problems in the urinary tract
A problem with the structure of the urinary tract may be present from birth. The urinary tract can develop a blockage at any level between the kidney and the urethra (the tube that transports urine from the bladder to outside the body). There are many reasons for such a blockage including kidney stones, scar tissue from previous infections, or an enlarged prostate gland. Abnormal function of the urinary tract can also lead to damage to the kidney. Examples include backfllow of urine into the ureter (the tube from the kidney to the bladder), or damaged bladder muscle leading to retention of urine. If waste can’t leave the body, your health is at risk.