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.

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.

Chronic kidney disease (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.

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
CausesSudden kidney injuryKidney damage that develops more gradually
Risk factorsA critical injury or illness; older age; hospitalizationHigh blood pressure, diabetes, or heart disease; family history
SymptomsDevelop suddenly over a few hours or days. May include decreased urination, swelling, and confusionSymptoms develop over time and may include weight loss, brain fog, fatigue, and more
DiagnosisCombination of blood and urine tests, and possible kidney ultrasoundMultiple tests over time, including glomerular filtration rate (GFR) blood test, blood urea nitrogen (BUN) test, albumin urine test, creatinine blood test, a low GFR rate, or blood protein test
TreatmentHospitalization and dialysisManaging the underlying causes; dialysis or kidney transplant for later stages

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 CKD affects roughly 1 in 5 adults with high blood pressure and 1 in 3 adults with diabetes.

While symptoms may vary, some of the most common ones associated with ARF include:

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:

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:

  • a future incidence of ARF
  • developing CKD (possibly within 1 year)
  • heart disease
  • stroke

CKD may also lead to the above complications, as well as:

  • anemia
  • malnutrition
  • bone diseases

Doctors diagnose CKD in five stages, with lower stages indicating milder disease. Stages 4 and 5 are considered the most severe forms of CKD.

You may dialysis at stage 4. In the final advanced end stage renal failure, due to progressive CKD, you may be placed on the transplant list depending on certain tests.

Steps you can take to help your kidney health

You may be able to help protect your kidneys with the following steps:

Both CKD and ARF affect your kidneys, but they have key differenesv from the symptoms you experience, how they’re diagnosed, and how you treat each one.

Your healthcare team can best help you understand the similiarities and differences, and what steps you may need to treat each condition and protect your kidneys from more damage.