Renal failure occurs when the kidneys are no longer able to carry out their essential functions, including removing waste and toxins from the blood and helping to control blood pressure and the balance of hormones, fluids and minerals in the body. The onset of kidney failure may be acute or chronic, depending upon the underlying cause, which can be difficult to pinpoint. Urine and blood tests, along with a review of the patient's medical history, can help her doctor identify what led to the kidney damage.
Impaired Blood Flow
Any medical condition or injury that impairs blood flow to the kidneys can cause renal failure. Decreased blood flow can occur for a number of reasons. For example, the heart may fail to pump enough blood to supply the body’s vital organs as a result of damage from a heart attack, heart disease, cardiomyopathy--a weakening of the heart muscle--or a blood clot in the lungs, according to Merck.com.
A decrease in the amount of fluid surrounding the cells inside of the body can also affect normal blood flow. For example, severe dehydration or burns covering a large surface area of the skin can alter the normal balance of fluid and blood volume within the body and cause acute renal failure, according to MayoClinic.com.
Uncontrolled high blood pressure, or hypertension, can also impede blood flow to the kidneys. According to NephrologyChannel.com, hypertension is one of the most common causes of chronic kidney failure. Type 1 and type 2 diabetes are also a main cause of chronic renal failure as they often lead to high blood pressure and atherosclerosis, or a hardening of the arteries, in turn interfering with blood flow to the kidneys and other parts of the body.
Vascular nephropathy--disease of the vessels circulating blood to and from the kidneys--and glomerulonephritis--an acute or chronic condition in which the filtering structures of the kidneys become inflamed--can both occur as a result of high blood pressure and autoimmune conditions such as lupus and polyarteritis that affect the passage of blood through blood vessels, according to Merck.com.
Toxins and Medications
Certain substances can directly damage structures of the kidney that are essential for normal functioning, leading to renal failure. Ingestion of toxic chemicals and heavy metals, illicit drugs such as cocaine and certain types of medications, including chemotherapy drugs, antibiotics and high-contrast dyes used for X-rays and other scans can damage the filtering components of the kidneys, according to MayoClinic.com.
According to Merck.com, injury to the kidney’s tubules--structures that receive processed plasma and convert it to urine--is another underlying cause of renal failure. Certain medications such as nonsteroidal anti-inflammatory drugs like ibuprofen and immunosuppressive drugs like cyclosporine are known to damage the tubules and lead to acute and/or chronic kidney failure.
Bladder-Related Conditions
When the flow of urine out of the body becomes blocked, the kidneys may become damaged. Bladder obstructions caused by bladder stones or an enlarged prostate gland and neurogenic bladder--a condition in which damage to the nerves leading from the spinal cord to the bladder causes the bladder to swell--are both known causes of chronic renal failure, according to NephrologyChannel.com. Obstructions in the ureter--the tube that carries urine from the kidneys to the bladder--caused by trauma, surgical injury, tumors or congenital defects can also lead to acute renal failure, according to Merck.com.
