What Is Kidney Failure? Symptoms, Causes, Diagnosis and Treatment

Created: 20.08.2024 · Last Updated: 13.08.2026 · Category: Nephrology · Prepared by the Academic Hospital Web and Editorial Board.

What Is Kidney Failure?

Kidney failure is an advanced clinical state in which the kidneys have lost enough function that they can no longer adequately regulate waste products, excess fluid and electrolytes.

The kidneys also contribute to blood-pressure control, red-blood-cell production, acid-base balance and bone and mineral metabolism.

Severe loss of kidney function may therefore lead to fluid overload, electrolyte abnormalities, anaemia, metabolic acidosis and bone-mineral disorders.

Chronic kidney disease and kidney failure are not synonymous. CKD includes a broad spectrum from early kidney damage to advanced disease. Kidney failure refers to severe loss of kidney function.

What Is the Difference Between Acute Kidney Injury and Chronic Kidney Disease?

Acute Kidney Injury

Acute kidney injury (AKI) is a sudden deterioration in kidney function over hours or days.

Possible causes include severe dehydration, infection or sepsis, impaired circulation, medicines or toxins, urinary obstruction and diseases directly affecting kidney tissue.

Kidney function may partially or completely recover when the underlying cause is identified and treated, although severe AKI can increase the future risk of chronic kidney disease.

Chronic Kidney Disease

Chronic kidney disease (CKD) is an abnormality of kidney structure or function that persists for at least three months.

It may progress slowly over years and can cause no symptoms during its early stages.

Who Is at Risk of Kidney Disease?

Important risk factors include:

  • Diabetes
  • High blood pressure
  • Cardiovascular disease
  • A family history of kidney disease
  • Previous acute kidney injury
  • Inherited kidney disease
  • Recurrent kidney stones or urinary obstruction
  • Systemic or autoimmune diseases affecting the kidneys

Certain medicines can also affect kidney function, particularly when used at high doses, for prolonged periods or in people who already have kidney disease.

Not every herbal product or protein supplement causes kidney failure. However, products of uncertain composition, excessive doses and some supplements used by people with pre-existing kidney disease may present risks.

What Can Cause Kidney Failure?

Important causes of chronic kidney disease include diabetes, high blood pressure, glomerular diseases, inherited polycystic kidney disease, prolonged urinary obstruction and systemic or autoimmune diseases.

What Are the Symptoms of Kidney Failure?

Early CKD may cause no symptoms.

With advanced loss of kidney function, possible symptoms include:

  • Fatigue and weakness
  • Loss of appetite
  • Nausea or vomiting
  • Swelling of the feet, ankles or legs
  • Shortness of breath
  • Itching
  • Muscle cramps
  • Sleep problems
  • Difficulty concentrating
  • Marked reduction in urine output in some patients
Producing a normal amount of urine does not prove that kidney function is normal. Many people with CKD continue to produce urine until advanced stages.

How Is Kidney Disease Diagnosed?

Assessment commonly includes both blood and urine tests.

  • Serum creatinine
  • Estimated glomerular filtration rate (eGFR)
  • Urine albumin-to-creatinine ratio (UACR)
  • Urinalysis
  • Electrolytes
  • Complete blood count

Ultrasound, immune testing, genetic tests or kidney biopsy may be needed depending on the suspected cause.

What Is eGFR?

eGFR is an estimated measure of how effectively the kidneys filter the blood.

A low result may indicate reduced kidney function, but a single result does not necessarily establish chronic kidney disease.

Kidney abnormalities generally need to persist for at least three months to meet the definition of CKD.

An eGFR below 15 ml/min/1.73 m² represents advanced loss of kidney function, but dialysis is not automatically started based on this number alone.

Why Is Urine Albumin Important?

Healthy kidneys normally keep most albumin in the bloodstream.

Damage to the kidney's filtering structures can allow albumin to enter the urine.

The urine albumin-to-creatinine ratio (UACR) helps identify kidney damage and assess the risk of progression and cardiovascular disease.

How Is Chronic Kidney Disease Treated?

The goals of treatment are to preserve kidney function where possible, slow progression and reduce complications and cardiovascular risk.

Management may include:

  • Blood-pressure control
  • Diabetes management
  • Smoking cessation
  • Reducing excess dietary sodium
  • Appropriate physical activity
  • Reviewing medicines that may harm kidney function
  • Renin-angiotensin system blockade in appropriate patients with albuminuria
  • Kidney-protective therapies such as SGLT2 inhibitors in appropriate patients
  • Management of anaemia, electrolyte abnormalities, acidosis and bone-mineral disorders

Diet and Kidney Disease

There is no single diet that is appropriate for everyone with CKD.

Dietary recommendations depend on kidney function, dialysis status, potassium and phosphate levels, albuminuria, nutritional status and associated conditions.

Sodium reduction may help control blood pressure and fluid retention.

Not everyone with kidney disease needs a very low-protein, low-potassium or low-phosphate diet. Unnecessary restriction can contribute to malnutrition, so dietary treatment should be individualised.

When Is Dialysis Needed?

Dialysis partially replaces some functions that failing kidneys can no longer perform.

The main types are:

  • Haemodialysis
  • Peritoneal dialysis

The decision to start dialysis is not based solely on creatinine or eGFR.

It may be required when severe complications develop, including refractory fluid overload, dangerous hyperkalaemia, severe metabolic acidosis or clinically important uraemic symptoms.

There is no single eGFR value at which every patient must automatically start dialysis.

What Is Kidney Transplantation?

Kidney transplantation involves surgically placing a healthy kidney from a living or deceased donor into an eligible patient with kidney failure.

In appropriate patients, a functioning kidney transplant can provide more complete kidney function than dialysis.

However, transplantation requires careful selection, regular lifelong follow-up and long-term immunosuppressive treatment to reduce the risk of rejection.

Kidney transplantation is a treatment for kidney failure, not a permanent cure.

How Can Kidney Health Be Protected?

  • Keep blood pressure under control.
  • Manage blood glucose if you have diabetes.
  • Avoid smoking.
  • Maintain a healthy body weight.
  • Stay physically active.
  • Avoid excessive salt intake.
  • Avoid unnecessary use of potentially kidney-harming medicines and unregulated supplements.
  • Have kidney function checked if you are at increased risk.

Which Symptoms Require Urgent Medical Assessment?

  • Sudden major reduction or absence of urine
  • Rapidly worsening shortness of breath
  • Rapidly increasing generalised swelling
  • Confusion or marked drowsiness
  • Severe weakness
  • Persistent vomiting with inability to maintain hydration

Have Your Kidney Function Assessed

If you have diabetes, high blood pressure, a family history of kidney disease or concerns about kidney function, eGFR, urine albumin and other appropriate tests can be evaluated together.

Frequently Asked Questions

What is kidney failure?
Kidney failure is an advanced clinical state in which the kidneys have lost enough function that they can no longer adequately regulate waste products, excess fluid and electrolytes. Severe kidney failure can occur in advanced chronic kidney disease or during severe acute kidney injury.
Are chronic kidney disease and kidney failure the same thing?
No. Chronic kidney disease is a broad condition involving abnormalities of kidney structure or function lasting at least three months. Kidney failure refers to advanced loss of kidney function.
Does kidney disease cause symptoms in its early stages?
Not always. CKD can remain asymptomatic for a long time, which is why tests such as eGFR and urine albumin are important in people with diabetes, hypertension or other risk factors.
What eGFR indicates kidney failure?
An eGFR below 15 ml/min/1.73 m² represents advanced loss of kidney function. However, a single result does not establish chronic disease and dialysis is not started on the eGFR value alone.
Does a normal creatinine level guarantee healthy kidneys?
No. Creatinine is affected by age, muscle mass and other factors. eGFR and urine albumin-to-creatinine ratio provide additional information about kidney health.
Can kidney failure improve?
Kidney function may partially or completely recover after acute kidney injury if the underlying cause can be treated. Structural damage in chronic kidney disease is generally not completely reversible, although progression can often be slowed.
At what eGFR is dialysis started?
There is no single eGFR threshold at which dialysis must be started for every patient. Symptoms, fluid status, potassium and acid-base abnormalities, uraemic complications, nutritional status and the overall clinical picture are considered together.
Does a kidney transplant permanently cure kidney failure?
Kidney transplantation is an effective kidney replacement treatment for eligible patients, but it is not a permanent cure. Regular follow-up and long-term immunosuppressive medication are required after transplantation.
Academic Hospital note: Kidney disease may cause no symptoms during its early stages. In people with diabetes, high blood pressure, a family history of kidney disease or other risk factors, serum creatinine and eGFR should be considered together with urine albumin testing when appropriate. You can book an appointment.

References

  1. Academic Hospital. Kidney Failure
  2. KDIGO. 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease
  3. KDIGO. Acute Kidney Injury and Acute Kidney Disease
  4. National Institute of Diabetes and Digestive and Kidney Diseases. Chronic Kidney Disease Tests and Diagnosis
  5. National Institute of Diabetes and Digestive and Kidney Diseases. What Is Kidney Failure?
  6. National Institute of Diabetes and Digestive and Kidney Diseases. Choosing a Treatment for Kidney Failure