Kidney (Renal) Failure

Many people may have significantly reduced kidney function and not be aware of it. The symptoms of kidney failure can differ based on how bad the kidney failure is, how quickly it is worsening and what is causing it.

There are two main types of kidney (renal) failure: acute (sudden) and chronic (over time).

Acute Renal Failure – more commonly known today as “acute kidney injury”(AKI)

AKI occurs when the kidneys suddenly stop filtering waste products from the blood.

The signs of AKI can be:

• swelling of the hands, feet and face (edema)
• internal bleeding
• confusion
• seizures
• coma
• abnormal blood and urine tests
• high blood pressure

Chronic Kidney Disease (CKD; previously known as Chronic Renal Failure – CRF)

CKD builds slowly with very few symptoms in its early stages.

A patient with CKD may not have any symptoms until kidney function declines to 20% or less. At that stage, these signs may appear:

• abnormal blood and urine tests
• high blood pressure
• low red blood cell count (anemia)
• nausea
• vomiting
• metal taste in your mouth
• loss of appetite
• shortness of breath
• numbness and tingling
• confusion
• coma
• seizures
• easy bruising
• itching
• fatigue
• muscle twitches and cramps
• weak bones that break easily
• swelling of the hands, feet and face (edema)

AKI is most likely to happen with:

• prolonged time with low blood pressure
• swelling (inflammation) of the kidney (such as a reaction to a drug or infection)
• sudden blockage (such as by a kidney stone)
• very high blood pressure

With AKI, the kidney often returns to normal or near normal after the cause is treated.

CKD happens more gradually, often over years, and results in permanent loss of kidney function. The most common causes are:

• high blood sugar (diabetes)
• high blood pressure
• autoimmune diseases
• polycystic kidney disease
• blocked urinary tract

How well your kidneys filter blood determine overall kidney function. Several blood tests can estimate your kidney function. The most common blood test measure your creatinine level.

Kidney failure is most often found when the creatinine level is high, indicating that kidney function is reduced. Creatinine is a molecule made by your muscles. A normal kidney will remove creatinine from the blood stream and get rid of it in urine. More creatinine in the blood is a sign that the kidneys aren't cleaning the blood as well as they should. This test can spot something is wrong before a patient with kidney failure feels sick.

To treat AKI, you have to treat the cause (such as blood pressure that is too high or too low, a kidney stone or high blood sugar). Sometimes you need dialysis for a short time.

With CKD, treating the cause (such as high blood pressure and/or high blood sugar) can slow the disease. The goal is to prevent CKD from turning into advanced kidney disease, or end stage kidney disease (ESKD, formerly known as end stage renal disease, ESRD).

Dialysis

Dialysis is a way to remove extra salt, acid, potassium and waste products from the blood. The two types of dialysis are hemodialysis and peritoneal dialysis.

Hemodialysis: For hemodialysis, blood is removed from your body and filtered and cleaned through a machine, and then returned to your body. Hemodialysis is most often done three times a week for three to four hours at a time.

Diagram of Hemodialysis Treatment

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Peritoneal dialysis: Peritoneal dialysis is done through a tube permanently set in your abdomen. Fluid is then run into the abdomen, which then filters and cleans your blood, and then the fluid is drained from your body through the peritoneal dialysis tube. This process usually is done daily.

Kidney Transplant

A kidney transplant is a surgery that implants a healthier kidney from another person into your body. For people who are healthy enough for major surgery, a kidney transplant is usually the preferred way to treat end-stage kidney disease. Kidneys for transplant come from people who have agreed to donate their kidneys when they die (deceased donors) or donated by healthy people (living donors).

About 100,000 patients are on the wait list for a deceased donor kidney in the United States, but only a fraction of those patients receive a transplant each year due to a shortage of donated kidneys.

Updated November 2024.