During a kidney biopsy, your doctor uses a needle to remove a small sample of kidney tissue for lab testing. The biopsy needle is inserted through your skin and is often directed using the guidance of an imaging device, such as ultrasound.
If your signs and symptoms suggest that you have acute kidney failure, your doctor may recommend certain tests and procedures to verify your diagnosis. These may include:
- Urine output measurements. Measuring how much you urinate in 24 hours may help your doctor determine the cause of your kidney failure.
- Urine tests. Analyzing a sample of your urine (urinalysis) may reveal abnormalities that suggest kidney failure.
- Blood tests. A sample of your blood may reveal rapidly rising levels of urea and creatinine — two substances used to measure kidney function.
- Imaging tests. Imaging tests such as ultrasound and computerized tomography may be used to help your doctor see your kidneys.
- Removing a sample of kidney tissue for testing. In some situations, your doctor may recommend a kidney biopsy to remove a small sample of kidney tissue for lab testing. Your doctor inserts a needle through your skin and into your kidney to remove the sample.
Treatment for acute kidney failure typically requires a hospital stay. Most people with acute kidney failure are already hospitalized. How long you'll stay in the hospital depends on the reason for your acute kidney failure and how quickly your kidneys recover.
In some cases, you may be able to recover at home.
Treating the underlying cause of your kidney injury
Treatment for acute kidney failure involves identifying the illness or injury that originally damaged your kidneys. Your treatment options depend on what's causing your kidney failure.
Treating complications until your kidneys recover
Your doctor will also work to prevent complications and allow your kidneys time to heal. Treatments that help prevent complications include:
- Treatments to balance the amount of fluids in your blood. If your acute kidney failure is caused by a lack of fluids in your blood, your doctor may recommend intravenous (IV) fluids. In other cases, acute kidney failure may cause you to have too much fluid, leading to swelling in your arms and legs. In these cases, your doctor may recommend medications (diuretics) to cause your body to expel extra fluids.
- Medications to control blood potassium. If your kidneys aren't properly filtering potassium from your blood, your doctor may prescribe calcium, glucose or sodium polystyrene sulfonate (Kionex) to prevent the accumulation of high levels of potassium in your blood. Too much potassium in the blood can cause dangerous irregular heartbeats (arrhythmias) and muscle weakness.
- Medications to restore blood calcium levels. If the levels of calcium in your blood drop too low, your doctor may recommend an infusion of calcium.
- Dialysis to remove toxins from your blood. If toxins build up in your blood, you may need temporary hemodialysis — often referred to simply as dialysis — to help remove toxins and excess fluids from your body while your kidneys heal. Dialysis may also help remove excess potassium from your body. During dialysis, a machine pumps blood out of your body through an artificial kidney (dialyzer) that filters out waste. The blood is then returned to your body.
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
Lifestyle and home remedies
During your recovery from acute kidney failure, your doctor may recommend a special diet to help support your kidneys and limit the work they must do. Your doctor may refer you to a dietitian who can analyze your current diet and suggest ways to make your diet easier on your kidneys.
Depending on your situation, your dietitian may recommend that you:
- Choose lower potassium foods. Your dietitian may recommend that you choose lower potassium foods. High-potassium foods include bananas, oranges, potatoes, spinach and tomatoes. Examples of low-potassium foods include apples, cauliflower, peppers, grapes and strawberries.
- Avoid products with added salt. Lower the amount of sodium you eat each day by avoiding products with added salt, including many convenience foods, such as frozen dinners, canned soups and fast foods. Other foods with added salt include salty snack foods, canned vegetables, and processed meats and cheeses.
- Limit phosphorus. Phosphorus is a mineral found in foods, such as whole-grain bread, oatmeal, bran cereals, dark-colored colas, nuts and peanut butter. Too much phosphorus in your blood can weaken your bones and cause skin itchiness. Your dietitian can give you specific recommendations on phosphorus and how to limit it in your particular situation.
As your kidneys recover, you may no longer need to eat a special diet, although healthy eating remains important.
Preparing for your appointment
Most people are already hospitalized when they develop acute kidney failure. If you or a loved one develops signs and symptoms of kidney failure, bring up your concerns with your doctor or nurse.
If you aren't in the hospital, but have signs or symptoms of kidney failure, make an appointment with your family doctor or a general practitioner. If your doctor suspects you have kidney problems, you may be referred to a doctor who specializes in kidney disease (nephrologist).
Before your meeting with the doctor, write down your questions. Consider asking:
- What's the most like cause of my symptoms?
- Have my kidneys stopped working? What could have caused my kidney failure?
- What kinds of tests do I need?
- What are my treatment options and what are the risks?
- Do I need to go to the hospital?
- Will my kidneys recover or will I need dialysis?
- I have another health conditions. How can I best manage these conditions together?
- Do I need to eat a special diet, and if so, can you refer me to a dietitian to help me plan what to eat?
- Is there a generic alternative to the medicine you're prescribing me?
- Do you have any printed materials that I can take with me? What websites do you recommend?