What is chronic kidney disease?

Kidney disease (also called renal disease) is when your kidneys are damaged or don't function as they should. If you have kidney disease that lasts for more than 3 months, it's called chronic kidney disease (or CKD).

Your kidneys' main job is to clean your blood and make urine (wee) to get rid of waste products. When your kidneys don't work properly, waste and fluid build-up inside your body.

Chronic kidney disease gets worse over time. It can eventually lead to kidney failure. If you are diagnosed and treated early, you may be able to slow down or stop your disease getting worse.

About 1 in 10 Australian adults has signs of chronic kidney disease. Aboriginal and/or Torres Strait Islander people are twice as likely to have chronic kidney disease.

What are the symptoms of chronic kidney disease?

Chronic kidney disease is sometimes called a 'silent disease' because there may be no warning signs until your kidneys are severely damaged.

In the early stages of CKD you probably won't have any symptoms. As kidney disease progresses (gets worse), you may start feeling unwell.

You may notice changes in your urine, such as:

• waking up at night to go to the toilet
• changes in how your urine looks, such as frothy or foaming urine or a change in colour
• blood in your urine

Other symptoms may include:

• tiredness and low energy
• loss of appetite, nausea and vomiting
• bad breath or a metallic taste in your mouth
• puffiness in your ankles or around your eyes
• itching
• shortness of breath
• restless legs

What causes chronic kidney disease?

The most common cause of chronic kidney disease in Australia is diabetes. This is because high blood sugar levels damage the blood vessels in your kidneys. Chronic kidney disease caused by diabetes is also called diabetic nephropathy.

Other causes of kidney damage include:

• high blood pressure (hypertension)
• polycystic kidney disease
• inflammation of the kidneys (glomerulonephritis) — this condition can develop after an infection or due to other causes
• blockage of the urinary tract
• taking some medicines long term, such as some pain-relief medicines or lithium

What are the risk factors for chronic kidney disease?

You are at higher risk of developing chronic kidney disease if you:

• have cardiovascular disease
• have diabetes or high blood pressure
• have family members with kidney disease
• are living with obesity
• smoke or vape (or have smoked in the past)
• are over 60 years of age, or over 18 years of age for Aboriginal and/or Torres Strait Islander people
• have had an acute kidney injury

When should I see my doctor?

If you notice any symptoms of chronic kidney disease, see your doctor.

Your body can cope with your kidneys not working properly for quite a while, so you may not have any symptoms. If you have any risk factors for kidney disease, it's very important to get your kidney function checked regularly. Ask your doctor how often you should be tested.

How is chronic kidney disease diagnosed?

Your doctor will ask about your symptoms and overall health. They will examine you and check your blood pressure.

Tests that help diagnose chronic kidney disease include:

• urine tests — to look for blood and albumin, a protein that is released by damaged kidneys
• blood tests — including your level of urea and creatinine (waste products in the blood) and estimated glomerular filtration rate (eGFR), which is a measurement of your kidney function
• an ultrasound or x-ray of your kidneys and urinary tract

You may need other tests to work out the cause of your chronic kidney disease.

If these tests show you have kidney damage, your doctor will work out what stage your disease is at. They may refer you to a nephrologist (specialist kidney doctor).

What are the stages of chronic kidney disease?

There are 5 stages of kidney disease. Your stage of kidney disease is based on your:

• eGFR
• ACR (albumin-to-creatinine ratio) — this is a measure of protein in your urine and helps determine whether your kidney disease is mild, moderate or severe

Stages 1-2

• Stage 1 — your eGFR result will be more than 90
• Stage 2 — your eGFR result will be between 60 and 89

At these stages, your eGFR is not low, but you will be diagnosed with CKD if you have protein or blood in your urine, or if an ultrasound shows damage to your kidneys.

Stage 3

• Stage 3a — your eGFR result will be between 45 and 59
• Stage 3b — your eGFR result will be between 30 and 44

At this stage there are usually no symptoms, so you may not know you have CKD. Being diagnosed with CKD at this stage can slow down the damage to your kidneys and lower your risk of complications.

Stage 4

• Stage 4 — your eGFR result will be between 15 and 29

At this stage, the risk of complications, kidney failure and death get higher.

Stage 5

• Stage 5 — your eGFR result will be less than 15

This stage represents kidney failure.

How is chronic kidney disease treated?

Chronic kidney disease cannot be cured, but treatments can help prevent it from getting worse. Your treatment will depend on the stage of your kidney disease and whether it is mild, moderate or severe.

Mild CKD

In the early stages of CKD, the goal of treatment is to prevent your kidney disease from getting worse and to prevent you from developing cardiovascular disease.

It's important to maintain a healthy lifestyle.

Your doctor may prescribe you medicines to lower your blood pressure, blood sugar levels and cholesterol.

Many medicines can affect your kidneys. Make sure you tell your doctor about any medicines you are taking, including natural or herbal remedies.

You should see your doctor every 12 months.

Moderate and severe CKD

When your kidney disease gets worse, it's important to continue healthy lifestyle measures and take any medicines that your doctor has prescribed.

Your doctor may ask you to stop or change the dose of medicines that may affect your kidneys. In particular, it's best to avoid anti-inflammatory medicines (NSAIDs).

You may also need other treatments if you develop any complications of chronic kidney disease.

You should see your doctor every 3 to 6 months.

Kidney failure

When your kidneys can no longer work effectively, the following options are available:

• kidney transplant
• dialysis
• supportive care

Lifestyle measures

Eating a healthy diet is important. Try to follow these guidelines:

• Eat a variety of healthy foods.
• Limit processed foods and sugar.
• Limit salt to less than 5g a day.
• Limit your intake of saturated and trans fats.
• Drink plenty of water — avoid becoming dehydrated.
• Follow protein levels your health team recommends, based on your CKD stage

You may need to see a dietitian for specific instructions about what to eat or drink.

You should also be physically active on most days of the week:

• Aim for at least 2 and a half hours of physical activity each week.
• Make sure you do some muscle strengthening exercises.

Here are some other changes you should make:

• Avoid smoking and vaping.
• Limit alcohol.
• Lose weight if you are living with obesity.

What are the complications of chronic kidney disease?

Kidney disease can cause many different problems, including:

• fluid in your lungs
• high potassium levels in your blood
• anaemia
• weak bones and fractures
• problems with concentrating, memory and thinking
• pregnancy complications

Can chronic kidney disease be prevented?

Here are some things you can do to help keep your kidneys healthy:

• Maintain a healthy weight.
• Do not smoke.
• Keep your blood pressure under control.
• If you have diabetes, keep your blood sugar level under control.

Resources and support

For more information about chronic kidney disease and kidney health in general, visit Kidney Health Australia or call their Kidney Helpline on 1800 454 363.

Take a quick online test to check your risk of chronic kidney disease.

You can read about diabetes and kidney health at Diabetes Australia.

Languages other than English

Kidney Health Australia has information about kidney disease in a number of community languages.

Information for Aboriginal and/or Torres Strait Islander peoples

Kidney Health Australia has resources for Aboriginal and/or Torres Strait Islander people.