Acute renal failure comes on suddenly, usually in people who are already critically ill. Chronic kidney disease develops gradually and may not cause symptoms until much later. Treatments differ, but both may involve dialysis.
Acute renal failure (ARF) and chronic kidney disease (CKD) are two serious kidney-related conditions. While ARF has a rapid onset, CKD develops more gradually.
Learn more about the key differences between ARF and CKD, including the causes, symptoms, and overall outlook.
Also called acute kidney injury or acute kidney failure, ARF describes sudden and severe kidney damage or failure. It develops from a buildup of waste in your bloodstream that the kidneys can’t get rid of as they should.
ARF develops over a few hours and up to a few days. A doctor may diagnose ARF with a combination of blood and urine tests and possibly an ultrasound of the kidneys.
The possible causes of ARF include:
- low blood pressure
- damage from the overuse of nonsteroidal anti-inflammatory drugs (NSAIDs)
- sudden blood or fluid losses
- heart attack or organ failure
- injuries or burns
- major surgery
- certain cancers, such as prostate or cervical cancer
- kidney inflammation
- blocked urinary tract from kidney stones, blood clots, or enlarged prostate
CKD is another type of kidney condition characterized by damage to your kidneys. But unlike ARF, CKD develops more gradually. ARF may also be a risk factor for developing CKD, and vice versa.
With CKD, your kidneys become unable to filter wastes from your bloodstream. This can lead to other health complications, such as heart disease.
Some possible causes of CKD include:
- high blood pressure
- diabetes
- heart disease
- a family history of kidney disease or kidney failure
To diagnose CKD, having multiple test results over time helps determine whether kidney damage is acute or chronic. A doctor may use any of the following tests:
- glomerular filtration rate (GFR) blood test
- blood urea nitrogen (BUN) test
- albumin urine test
- creatinine blood test
A low GFR rate can indicate problems with your kidneys. The presence of some proteins in your blood or urine could mean your kidneys are damaged.
ARF is most common in older adults and people already in the hospital for a critical illness. The risk of CKD may also increase with age, but it always develops more gradually.
Experts estimate that
While symptoms may vary, some of the most common ones associated with ARF include:
- decreased urination
- fatigue
- swelling around your ankles or legs
- chest pain
- confusion
- shortness of breath
- nausea
- seizures
- coma
Unlike ARF, CKD usually doesn’t have symptoms at first. As kidney damage progresses, CKD may cause swelling in your legs and feet due to fluid buildup.
Other CKD symptoms could indicate that the condition is in an advanced stage. Possible signs include:
- increased or decreased urination
- fatigue
- headaches
- itchy or dry skin
- loss of appetite and weight loss
- nausea or vomiting
- muscle cramps
- shortness of breath
- brain fog
- chest pain
Most people with ARF require hospitalization. You may already be in the hospital before developing an ARF. The length of your hospital stay depends on the severity of ARF and the treatment response. A doctor may also recommend dialysis.
The focus of treatment for CKD is to prevent any kidney damage from worsening. Depending on the underlying cause of your condition, this may include treating and managing diabetes or high blood pressure.
You may require dialysis or a kidney transplant in later stages.
Having ARF increases your risk for:
CKD may also lead to the above complications, as well as:
- anemia
- malnutrition
- bone diseases
Doctors further diagnose CKD as stage 1 to 5, with lower stages indicating milder disease. Stages 4 and 5 are considered the most severe forms of CKD. At this point, you may need dialysis or a kidney transplant because your kidneys are no longer functional.
You may be able to help protect your kidneys with the following steps:
- Control your blood pressure (
140/90 mm Hg or lower). - Monitor your blood glucose.
- Quit smoking if you smoke.
- Take medications as prescribed, including those that help manage high blood pressure and diabetes.
- Avoid NSAID overuse.
- Achieve and maintain a moderate weight.
- Exercise daily.
- Get enough sleep.
Below is a quick look at the key differences between ARF and CKD you may wish to discuss further with a doctor.
| ARF (AKI) | CKD | |
|---|---|---|
| Causes | Sudden kidney injury | Kidney damage that develops more gradually |
| Risk factors | A critical injury or illness; older age; hospitalization | High blood pressure, diabetes, or heart disease; family history |
| Symptoms | Develop suddenly and may include decreased urination, swelling, and confusion | Symptoms develop over time and may include weight loss, brain fog, fatigue, and more |
| Treatment | Hospitalization and dialysis | Managing the underlying causes; dialysis or kidney transplant for later stages |