DefinitionWhen you have kidney failure, one or both kidneys aren't able to work normally. The kidneys remove waste (in the form of urine) from the body. They also balance the water and electrolyte content in the blood by filtering salt and water.
Kidney failure is divided into two categories:
- Acute kidney failure —sudden loss of kidney function
- Chronic kidney failure —slow, gradual loss of kidney function
CausesKidney disease causes the tiny filters in the kidneys (called nephrons) to lose their ability to filter. Damage to the nephrons may occur suddenly after an injury or poisoning. But, many kidney diseases take years or even decades to cause damage that is noticeable.
The two most commons causes are:
- Diabetes —high blood sugar can damage nephrons
- High blood pressure —severe high blood pressure can damage blood vessels in the kidneys
- Polycystic kidney disease
- Birth defects
- Bilateral renal artery stenosis
- Severe trauma
- Viral infections (eg, hepatitis B, hepatitis C, HIV/AIDS)
- Long-term use of medicines that contain aspirin, acetaminophen, ibuprofen
- Abnormal build-up of substances within the kidneys (eg, amyloidosis, protein build-up)
- Toxic reaction to drugs or x-ray dyes
- Systemic diseases (eg, lupus, polyarteritis, Wegener’s granulomatosis
- Conditions that severely decrease the amount of blood (eg, burns, pancreatitis, peritonitis)
- Conditions that make it difficult to urinate (eg, enlarged prostate, kidney stones, tumors)
RiskThese factors increase your chance of developing kidney failure. Tell your doctor if you have any of these risk factors:
- Genetics: polycystic kidney disease, type 1 diabetes
- Race: African Americans
- High blood pressure
- Lupus or other autoimmune diseases
- Long-term use of pain medications containing aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) in high doses
- Liver failure, jaundice
- Respiratory failure
- Recent open heart surgery
- Recent surgery on an abdominal aortic aneurysm
- Condition that obstructs urine flow
- Enlargement of the prostate gland
SymptomsSome kidney diseases begin without any symptoms. As the disease progresses, some of the following symptoms may develop:
- Fluid retention
- Swollen hands and feet, numbness of hands and feet, itchy skin
- Fatigue, insomnia
- Low urine output (or no urine output in severe cases), frequent urination
- Altered consciousness
- Loss of appetite, malnutrition
- Sores, bad taste in the mouth
- Nausea, vomiting
- Muscle cramps and twitches
- Shortness of breath
- High blood pressure
- Low temperature
- Seizures, coma
- Breath smelling like urine
- Yellowish-brownish skin tone
DiagnosisThe doctor will ask about your symptoms and medical history, and perform a physical exam. Tests may include:
If the kidneys are not working properly, the blood will show:
- An increase in:
- Parathyroid hormone
- Blood urea nitrogen
- A decrease in serum calcium
- 24-hour urine protein test —to see if your body is losing protein in the urine
- Renal ultrasound —uses sound waves to study the renal system (kidneys, bladder, and ureters)
- Biopsy —removal of a sample of kidney tissue to test for kidney cell functioning
- An increase in:
TreatmentMost chronic kidney diseases are not reversible. But, there are treatments that may be used to help preserve as much kidney function as possible. In the cases of acute renal failure, treatment focuses on the illness or injury that caused the problem.
- Restricting fluids
- Doing daily weight checks
- Eating a high-carbohydrate, low-protein diet
Medications used in acute or chronic kidney failure may include:
- Diuretics —to flush out the kidneys, increase urine flow, and rid the body of excess sodium (eg, furosemide, mannitol)
- Blood pressure medications (eg, ACE inhibitors)
- Medicine to treat anemia (eg, epoetin alfa [Epogen, Procrit], ascorbic acid [vitamin C])
- Sodium polystyrene sulfonate or insulin in dextrose—to control high potassium levels
- Calcium acetate —to control high phosphorus levels
Dialysis is a process that takes over for the kidneys and filters waste from the blood. This may be done for short-term, until kidney function improves. Or, it may be done you have a kidney transplant.
This may be the right option for some patients. Having a successful transp lant depends on many factors, such as what is causing the kidney damage and your overall health.
Your doctor will monitor these blood levels:
- Red blood cells
The following are steps to help your kidneys stay healthy longer:
- Have your blood pressure checked regularly. Take medication to control high blood pressure.
- If you have diabetes, control your blood sugar. Ask your doctor for help.
- Avoid the chronic use of pain medications.
- If you have chronic kidney disease, you may need to limit how much protein you eat. Talk to a dietician.
- Limit how much cholesterol and sodium you eat.
- If you have severe kidney disease, limit how much potassium you eat. If your kidneys are failing, get help from a dietician.
PreventionIn some cases, you cannot prevent kidney failure. But there are some steps you can take that will lower your risk:
- Maintain normal blood pressure.
- If you have diabetes, control your blood sugar.
- Avoid long-term exposure to toxic substances, such as lead and solvents.
- Do not abuse alcohol or over-the-counter pain medication.
- Limit the amount of drugs toxic to the kidney.
- If you have chronic kidney failure, talk to your doctor before you become pregnant.