Kidneys failure is a condition where the kidneys stop working or injury keeps them from filtering properly. In kidney failure, these bacteria and salts build up and can have bad effects on the heart, brain, lungs, and other organs.

Kidney failure can occur from an acute situation or from chronic problems.

In acute renal failure, kidney function is lost rapidly and can occur from a variety of insults to the body. The list of causes is often categorized based on where the injury has occurred.

Prerenal causes (pre=before + renal=kidney) causes are due to decreased blood supply to the kidney. Examples of prerenal causes are:

• Hypovolemia (low blood volume) due to blood loss
• Dehydration from loss of body fluid (vomiting, diarrhea, sweating, fever )
• Poor intake of fluids
• Medication, for example, diuretics ("water pills") may cause excessive water loss.
• Loss of blood supply to the kidney due to obstruction of the renal artery or vein.

Renal causes (damage directly to the kidney itself) include:

• Sepsis: The body's immune system is overwhelmed from infection and causes inflammation and shutdown of the kidneys. This usually does not occur with urinary tract infections.
• Medications: Some medications are toxic to the kidney, including nonsteroidal anti-inflammatory drugs like ibuprofen and naproxen. Others are antibiotics like aminoglycosides [gentamicin (Garamycin), tobramycin], lithium (Eskalith, Lithobid), iodine-containing medications such as those injected for radiology dye studies.
• Rhabdomyolysis: This is a situation in which there is significant muscle breakdown in the body, and the degeneration products of muscle fibers clog the filtering system of the kidneys. Often occurring because of trauma and crush injuries, it can also be caused by some medications used to treat high cholesterol.
• Multiple Myeloma
• Acute glomerulonephritis or inflammation of the glomeruli, the filtering system of the kidneys. Many diseases can cause this inflammation including systemic lupus erythematosus, Wegener's granulomatosis, and Goodpasture syndrome.

Post renal causes (post=after + renal= kidney) are due to factors that affect outflow of the urine:

• Obstruction of the bladder or the ureters can cause back pressure when there is no place for the urine to go as the kidneys continue to work. When the pressure increases enough, the kidneys shut down.
• Prostatic hypertrophy or prostate cancer may block the urethra and prevents the bladder from emptying.
• Tumors in the abdomen that surround and obstruct the ureters.
• Kidney stones

Chronic renal failure develops over months and years. The most common causes of chronic renal failure are related to:

• Poorly controlled diabetes
• Poorly controlled high blood pressure
• Chronic glomerulonephritis

Less common causes:

• Polycystic Kidney Disease
• Reflux nephropathy
• Kidney stones
• Prostate disease

• In the beginning, kidney failure may be asymptomatic (not producing any symptoms). As kidney function decreases, the symptoms are related to the inability to regulate water and electrolyte balances, to clear waste products from the body, and to promote red blood cell production. Lethargy, weakness, shortness of breath, and generalized swelling may occur. Unrecognized or untreated, life-threatening circumstances can develop.
• Metabolic acidosis, or increased acidity of the body due to the inability to manufacture bicarbonate, will alter enzyme and oxygen metabolism, causing organ failure.
• Inability to excrete potassium and rising potassium levels in the serum (hyperkalemia) is associated with fatal heart rhythm disturbances (arrhythmias).
• Rising urea levels in the blood (uremia) can affect the function of a variety of organs ranging from the brain (encephalopathy) with alteration of thinking, to inflammation of the heart lining (pericarditis), to decreased muscle function because of low calcium levels (hypocalcemia).
• Generalized weakness can be due to anemia, a decreased red blood cell count, because lower levels of erythropoietin do not adequately stimulate the bone marrow. A decrease in red cells equals a decrease in oxygen-carrying capacity of the blood, resulting in decreased oxygen delivery to cells for them to do work; therefore, the body tires quickly. As well, with less oxygen, cells more readily use anaerobic metabolism (an=without + aerobic=oxygen) leading to increased amounts of acid production that cannot be addressed by the already failing kidneys.
• As waste products build in the blood, loss of appetite, lethargy, and fatigue become apparent. This will progress to the point where mental function will decrease and coma may occur.
• Because the kidneys cannot address the rising acid load in the body, breathing becomes more rapid as the lungs try to buffer the acidity by blowing off carbon dioxide. Blood pressure may rise because of the excess fluid, and this fluid can be deposited in the lungs, causing congestive heart failure.

Prevention is always the goal with kidney failure. Chronic disease such as hypertension and diabetes are devastating because of the damage that they can do to kidneys and other organs. Lifelong diligence is important in keeping blood sugar and blood pressure within normal limits. Specific treatments are dependent upon the underlying diseases.

Once kidney failure is present, the goal is to prevent further deterioration of renal function. If ignored, the kidneys will progress to complete failure, but if underlying illnesses are addressed and treated aggressively, kidney function can be preserved, though not always improved.

Diet
Diet is an important consideration for those with impaired kidney function. Consultation with a dietician may be helpful to understand what foods may or may not be appropriate. Since the kidneys cannot easily remove excess water, salt, or potassium, they may need to be consumed in limited quantities. Foods high in potassium include bananas, apricots, and salt substitutes.
Phosphorus is a forgotten chemical that is associated with calcium metabolism and may be elevated in kidney failure. Too much phosphorus can leech calcium from the bones and cause osteoporosis and fractures. Foods with high phosphorus content include milk, cheese, nuts, and cola drinks.

Medications
Medications may be used to help control some of the issues associated with kidney failure.

• Phosphorus-lowering medications [calcium carbonate (Caltrate), calcitriol (Rocaltrol), sevelamer (Renagel)]
• Red blood cell production stimulation [erythropoietin, darbepoetin (Aranesp)]
• Red blood cell production (iron supplements)
• Blood pressure medications
• Vitamins

Once the kidneys fail completely, the treatment options are limited to dialysis or kidney replacement by transplantation.

Dialysis
Dialysis cleanses the body of waste products in the body by use of filter system. There are two types of dialysis.

Hemodialysis
Hemodialysis uses a machine filter called a dialyzer or artificial kidney to remove excess water and salt, to balance the other electrolytes in the body, and to remove waste products of metabolism. Blood flows through tubing into the machine, where it passes next to a filter membrane. A specialized chemical solution (dialysate) flows on the other side of the membrane. The dialysate is formulated to draw impurities from the blood through the filter membrane. Blood and dialysate never touch in the artificial kidney machine.

For this type of dialysis, access to the blood vessels needs to be surgically created so that large amounts of blood can flow into the machine and back to the body. Surgeons can build a fistula, a connection between a large artery and vein in the body, usually in the arm, that causes a large amount of blood flow into the vein. This makes the vein larger and its walls thicker so that it can tolerate repeated needle sticks to attach tubing from the body to the machine. Since it takes many weeks for a fistula to mature enough to be used, significant planning is required if hemodialysis is to be considered as an option.

If the kidney failure happens acutely and there is no time to build a fistula, special catheters may be inserted into the larger blood vessels of the arm, leg, or chest. These catheters may be left in place for up to three weeks. In some diseases, the need for dialysis will be temporary, but if the expectation is that dialysis will continue for a prolonged period of time, these catheters act as a bridge until a fistula can be planned, placed, and matured.

Dialysis treatments normally occur three times a week and last a few hours at a time. Most commonly, patients travel to an outpatient center to have dialysis, but home dialysis therapy is becoming an option for some.

Peritoneal dialysis
Peritoneal dialysis uses the lining of the abdominal cavity as the dialysis filter to rid the body of waste and to balance electrolyte levels. A catheter is placed in the abdominal cavity through the abdominal wall by a surgeon and is expected to remain there for the long-term. The dialysis solution is then dripped in through the catheter and left in the abdominal cavity for a few hours and then is drained out. In that time, waste products leech from the blood normally flowing through the lining of the abdomen (peritoneum).

There are benefits and complications for each type of dialysis. Not every patient can choose which type he or she would prefer. The treatment decision depends on the patient's illness and their past medical history along with other issues. Usually, the nephrologist (kidney specialist) will have a long discussion with the patient and family to decide what will be the best option available.

Yes. Some common ways to lower your risk of developing kidney failure are:

1. DO NOT use any prescription medicines, over-the-counter medicines, herbal or nutrition supplements without talking to your doctor.
2. Take your medicines for diabetes and high blood pressure regularly, and follow your doctor's instructions.
3. Let your doctor know about any reactions or allergies to medicines.

When the kidneys fail, bacteria and salts build up and can have bad effects on the heart, brain, lungs, and other organs.