What is kidney failure?
Kidney failure, also called renal failure, is a life-threatening condition in which there is a buildup of waste and fluid in the body due to severe deterioration of kidney function.
The kidneys are vital internal organs located in the upper abdomen. Normally, people have two bean-shaped kidneys that form a part of the urinary tract in the genitourinary system. Healthy kidneys function continuously and the body’s total blood supply passes through the kidneys several times each minute. A healthy body can continue to function with only one good kidney, as happens when someone volunteers to be a live kidney donor.
Kidney failure is caused by a variety of kidney diseases and other conditions that lead to kidney damage and deterioration of kidney function. Kidney failure can make it difficult or impossible for the kidneys to perform functions that are critical to life and your overall health including:
Filtering waste products and excess water and salts from the blood, which are then eliminated from the body through the ureters, bladder and urethra in the form of urine
Producing certain hormones, such as renin, which helps regulate blood pressure
Producing the active form of vitamin D (calcitriol)
Regulating electrolytes and other vital substances, such as sodium, calcium and potassium
Regulating the level and quality of fluid in the body
Stimulating red blood cell production
Once permanent kidney damage has occurred due to kidney disease or other conditions, such as uncontrolled hypertension, it cannot be reversed or cured. Seek prompt and regular medical care if you have risk factors for kidney disease, such as hypertension or diabetes. Following an effective treatment plan may slow or stop progression of kidney damage and minimize complications.
Kidney failure is a life-threatening condition because it critically affects the kidneys' ability to function normally. However, rapid diagnosis and treatment of underlying causes of acute kidney failure may reverse the condition.
Seek immediate medical care (call 911) for symptoms of kidney failure, such as severe shortness of breath, bloody stools or urine, sudden decrease in urine output or lack of urinating, severe flank pain, or a change in consciousness or alertness. Call 911 if anyone has overdosed on a drug or ingested a toxic substance, as these can lead to serious kidney damage.
What are the different types of kidney failure?
There are two general types of kidney failure:
Acute renal failure is a condition in which there is damage and deterioration of kidney function that occurs suddenly, generally over a period of days. Acute renal failure can be caused by such conditions as shock, acute pyelonephritis, urinary tract obstruction, or ingestion of certain toxic substances. In some cases, acute renal failure can be totally reversible without long-term consequences.
- Chronic kidney failure is a condition in which there is damage and deterioration of kidney function that persists over a long period of time (months to years). Chronic kidney failure is generally caused by long-term diseases, such as diabetes and hypertension. Once chronic kidney failure occurs, it cannot be reversed or cured.
What are the symptoms of kidney failure?
Symptoms of kidney failure, kidney disease, and other underlying causes of kidney failure can vary. General symptoms can include:
Cloudy or discolored urine
Dizziness upon attempted standing
Dry and itchy skin
Painful urination (dysuria)
Swelling of the feet or ankles
Vague symptoms, such as fatigue, difficulty sleeping, decreased appetite, fatigue, or generally not feeling well
Serious symptoms that might indicate a life-threatening condition
You should seek immediate medical care (call 911) for any of these symptoms of kidney failure or serious kidney disease:
Bloody stools or black, tarry stools
Change in level of consciousness or alertness, such as passing out or unresponsiveness
Severe flank pain that can move or radiate to the lower abdomen, groin, labia, or testicles
Shortness of breath or difficulty breathing
Sudden decrease in urination or lack of urination
You should also seek immediate medical care (call 911) if anyone has overdosed on a drug or ingested a toxic substance, as these can lead to serious kidney damage.
What are the stages of kidney failure?
Kidney failure is itself the final stage of chronic kidney disease (CKD), when cells in the kidneys become damaged and lose the ability to filter toxins from the bloodstream.
Stages of CKD are measured primarily by a person’s glomerular filtration rate (GFR), which reflects the level of kidney function. A normal GFR is 90 or higher.
Stage 5 (end-stage) CKD occurs when a person’s GFR is below 15, indicating kidney failure. The kidneys no longer function at a level to sustain life, and the person must receive a kidney transplant or go on dialysis in order to survive.
What causes kidney failure?
Kidney failure can be caused by a wide variety of underlying diseases, disorders or conditions that lead to kidney damage, such as obstruction, infection, malignancy (cancer), inflammation, deformity, toxic ingestion, or a reduced blood supply to the kidneys. Underlying causes include:
Diabetes, which can damage the kidneys over time
Diseases that cause inflammation and damage to the kidney, such as nephritis and glomerulonephritis
Hypertension (high blood pressure)
Infections, such as repeated bladder infections, pyelonephritis (kidney infection), or septicemia (blood infection)
Medications, such as intravenous (IV) drug abuse, overdose of certain drugs, or long-term use of certain medications, such as nonsteroidal anti-inflammatory drugs
Polycystic kidney disease (inherited disease that causes formation of large cysts in the kidneys that damage kidney tissue)
Reduced blood flow to the kidneys due to shock or renal artery stenosis (narrowing of the renal arteries)
Toxic exposure to poisonous substances
Trauma or injury to the kidney or arteries that supply blood to the kidneys
Urinary tract obstruction, which can be caused by a kidney stone, tumor, congenital deformity, or enlarged prostate gland
What are the risk factors for kidney failure?
Kidney failure can affect people of any age and any race or cultural background. However, a number of factors increase the risk of developing kidney failure. Risk factors include:
African American, Native American, Hispanic American, Asian, or Pacific Islander ethnicity
Age 65 years or older
Exposure to radiographic contrast material
Family history of kidney disease or kidney failure
Heart disease or liver disease
High cholesterol, atherosclerosis (buildup of plaque on the walls of the arteries), and peripheral artery disease (PAD)
Hypertension (high blood pressure)
Intravenous (IV) drug abuse
Long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen and naproxen)
Recent major surgery or serious or life-threatening illnesses, such as shock and septicemia (blood infection)
Reducing your risk of kidney failure
Not all people who are at risk for kidney failure will develop the condition. However, you may be able to lower your risk of developing kidney failure by:
Following your physician’s recommendation for using medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs)
Maintaining a healthy weight
Not using recreational and IV drugs
What is the diet and nutrition guidance for kidney failure?
Someone who has kidney failure likely has already been on a kidney-friendly diet throughout the earlier stages of chronic kidney disease (CKD). Diet is a key component of treatment for people with kidney disease in order to reduce stress on the kidneys and prevent further damage.
However, once a person has reached kidney failure, dialysis or a kidney transplant are the only options to treat kidney failure. When on dialysis, it is critical to follow a renal diet that prevents fluid and toxins from building up in the blood between treatments.
Your doctor and possibly a renal dietitian will guide you on your specific meal plan. Generally, people on dialysis need to limit their intake of:
Fluids: Extra fluids in the body can increase blood pressure and lead to other complications, such as heart failure. Dialysis treatments are also more effective with less fluid in the body. Along with limiting water and other drinks, it’s important to watch for foods with high water content, including many fresh fruits and vegetables. Experts recommend chewing gum or sucking on ice cubes, mints or hard candy to quench thirst without taking in excess liquid.
Phosphorus: This mineral is important for bone health. However, too much phosphorus when you are on dialysis could lead to excess levels in the blood, which can actually weaken bones and lead to bone disease.
Potassium: Found in nearly all foods, potassium is a mineral that helps with muscle function. When on dialysis, consuming too much potassium could lead to complications including arrhythmia, heart attack, and muscle weakness.
Sodium: Because the kidneys can no longer naturally control the amount of sodium in the bloodstream, it is important for someone receiving dialysis to limit sodium intake. A buildup of sodium in the blood causes the body to retain fluids, which can lead to high blood pressure and make dialysis treatments more difficult.
Different types of dialysis may require specific adjustments to your diet. Talk with your doctor or renal dietitian about your nutrition needs and the right meal plan for you while on dialysis.
How do doctors diagnose kidney failure?
If you are living with chronic kidney disease (CKD), your doctor and care team closely monitor your health and kidney function. In the later stages of CKD, doctors diagnose renal failure through procedures including:
Blood tests to determine blood cell counts, electrolyte levels, and kidney function
Renal ultrasound, also called sonography, is a noninvasive test in which a transducer is passed over the kidney, producing sound waves that bounce off the kidney and transmit a picture of the organ on a video screen. The test is used to determine the size and shape of the kidney and to detect a mass, kidney stone, cyst, or other obstruction or abnormality.
Kidney biopsy, in which tissue samples are removed (with a needle or during surgery) from the body for examination under a microscope to determine if cancer or other abnormal cells are present
Computed tomography scan (CT scan), a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images, both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.
If your doctors determine you have kidney failure, they will discuss your individual prognosis and guide you through your available treatment options.
What are the treatments for kidney failure?
Once your kidneys are in kidney failure, the only effective treatment options are:
Dialysis, a procedure that mechanically filters waste and toxins from the blood. In hemodialysis, blood is diverted from the body through a machine to remove chemicals, waste and fluid before clean blood re-enters the bloodstream. During peritoneal dialysis, a cleansing fluid flows through a tube (catheter) into your abdomen. The lining of your abdomen (peritoneum) acts as a natural filter and removes waste products from your blood. After a set period of time, the fluid with the filtered waste products flows out of your abdomen and is discarded.
Kidney transplant, a major surgical procedure using a healthy donor kidney to replace severely damaged kidneys. People who receive kidney transplants must take medications for the rest of their lives to prevent the body from rejecting the new kidney. After a successful kidney transplant, dialysis is no longer necessary.
People with acute kidney failure may be able to recover kidney function. However, chronic kidney failure is irreversible and can only be treated through dialysis or a successful kidney transplant.
How does kidney failure affect quality of life?
Living with chronic kidney disease (CKD) presents a variety of challenges, most prominently in the strict changes in diet required. People with CKD spend a significant amount of time researching nutrition labels and tracking consumption of fluids, sodium, and other minerals—all while trying to maintain proper nutrition and enjoyment of foods.
When kidney failure occurs and it is necessary for someone to go on dialysis, treatments can have an overwhelming impact on daily routines. Time spent managing and attending appointments can make it difficult to work, study, care for family members, or socialize. The side effects of dialysis have also been reported to lead to sleep disorders, chronic pain, and trouble with sexual intimacy. Generally, people on dialysis feel they have less independence and rely more on caregivers and healthcare providers.
Chronic kidney disease and kidney failure can have mental and emotional effects that can be difficult for others to understand. Seeking out support groups, both online and in person, can connect you with other people living with CKD or kidney failure to share comfort and advice.
What are the potential complications of kidney failure?
Kidney disease, and ultimately kidney failure, can lead to serious and life-threatening complications. You may be able to reduce your risk of serious complications by seeking regular medical care and following the treatment plan you and your healthcare professional design specifically for you. Complications include:
Gastrointestinal tract bleeding
Hypertension (high blood pressure)
Impaired mental functioning
Pleural effusion (fluid buildup around the lungs)
Swelling of the extremities
Does kidney failure shorten life expectancy?
Kidney failure is an urgent, life-threatening medical condition. Without dialysis or a transplant, life expectancy for people with kidney failure usually ranges from days to weeks. There is no cure for kidney failure, but treatment can extend your life by years.
Dialysis is not as efficient at cleaning toxins as healthy kidneys and can cause other health problems, but people on dialysis can live much longer and adapt their lives into a new routine that includes regular treatments.
A successful kidney transplant offers the best prognosis for someone with kidney failure. People with kidney transplants live up to 15 years longer than those on dialysis. Younger adults benefit the most from a kidney transplant, but people as old as 75 who receive a transplant live, on average, four more years than those on dialysis.