What is chronic kidney disease?

Kidney disease (also called renal disease) is a general term for when your kidneys are damaged and 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). When your kidneys don't work properly, wastes and fluid build-up inside your body.

Chronic kidney disease also can lead to other problems like heart disease and high blood pressure.

Chronic kidney disease usually gets worse. If you are diagnosed early, you can usually slow down or stop your disease getting worse. Chronic kidney disease can eventually lead to kidney failure. Getting treatment early is important.

About 1 in 10 Australian adults has signs of chronic kidney disease. Aboriginal and/or Torres Strait Islander peoples are twice as likely to have chronic kidney disease than non-Indigenous Australians.

What are the symptoms of chronic kidney disease?

Kidney disease is sometimes called a 'silent disease' because there may be no warning signs.

In the early stages of CKD you probably won't have any symptoms.

As kidney disease progresses (gets worse), you may start feeling unwell. Symptoms and signs of the middle and late stages of CKD can include:

• high blood pressure
• changes in the amount and number of times you pass urine, such as waking up in the night to go to the toilet
• changes in how your urine looks (such as frothy or foaming urine)
• blood in your urine
• puffiness in your legs, ankles or around the eyes
• pain in the kidney area

You may also have:

• tiredness and low energy
• loss of appetite
• headaches
• poor concentration
• itching
• shortness of breath
• nausea and vomiting

Other signs can include:

• bad breath and a metallic taste in the mouth
• pins and needles in the fingers or toes
• restless legs
• generally feeling unwell

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. This stops your kidneys from filtering wastes properly. About 4 in 10 cases of chronic kidney disease are caused by diabetes. Chronic kidney disease caused by diabetes is also called diabetic nephropathy.

High blood pressure can also lead to chronic kidney disease.

Inflammation of the kidneys (glomerulonephritis) can also lead to chronic kidney disease. This condition can be inherited or develop after an infection.

Other things that can increase your risk of chronic kidney disease include:

• having heart failure, or having had a heart attack or stroke
• having kidney disease in the family
• being overweight or obese
• smoking or having ever smoked
• being over 60 years of age
• being of Aboriginal and/or Torres Strait Islander origin
• a history of acute kidney injury (acute kidney failure)

Your kidneys can also be damaged by misuse of some pain-relief medicines, prescription medicines and illegal drugs.

When should I see my doctor?

If you notice any of the symptoms above, see your doctor.

Your body can cope with the kidneys not working properly for quite a while. People can lose 90% of their kidney function before they experience any symptoms. This makes it very important to take notice of any symptoms that do appear, and seek medical advice.

If you have one or more of the risk factors for kidney disease, it's very important to:

• look after your kidney health
• get your kidney function checked regularly

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How is chronic kidney disease diagnosed?

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

Tests that help to diagnose chronic kidney disease include:

• urine tests — to look for blood and/or albumin, a protein that is excreted by damaged kidneys
• blood tests — to measure the level of waste products in the blood; for example, creatinine and urea
• an estimated glomerular filtration rate (eGFR) test — a blood test that measures kidney function
• imaging tests — for example, an ultrasound or CT scan to look for abnormalities in your kidneys and urinary tract

If these tests show you have kidney damage, you may be referred to a nephrologist (specialist kidney doctor). They will try to work out the cause of your chronic kidney disease.

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What are the stages of chronic kidney disease?

There are 5 stages of kidney disease, each related to the level of kidney function and kidney damage.

To find out your stage of kidney disease, your doctor will check your:

• blood pressure
• eGFR
• ACR (albumin:creatinine ratio) — this is from a urine test

Your test results will vary depending on your age and the stage of your kidney disease.

Stages of kidney disease

Stages 1-2 (early-stage kidney disease)

You may not know you have early-stage kidney disease as there are usually no obvious signs.

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

Stages 3-4 (middle stage kidney disease)

This is the stage when most people are diagnosed with CKD. You may start to feel unwell as the waste builds up in your body and your blood pressure increases.

• Stage 3 — your eGFR result will be 30 to 59
• Stage 4 — your eGFR result will be 15 to 29

Stage 5 (kidney failure)

Sometimes, kidney disease can lead to kidney failure. People in this stage will need dialysis or a kidney transplant.

• Stage 5 — your eGFR result will be under 15

No matter what stage you're in, treatment can help slow the progress of kidney disease and reduce your chance of complications

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.

Stages 1-2: Your doctor will probably take steps to prevent you from developing cardiovascular disease. This may involve:

• lifestyle changes
• medicines to lower your blood pressure
• medicines to keep your blood sugar under control

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

Your doctor will need to see you every 12 months.

Stages 3-4: You may need treatment to:

• lower your blood pressure
• lower you blood fats
• lower your blood sugar

Your doctor will need to see you every 3 to 6 months.

Stage 5: When your kidneys can no longer function on their own, you may need:

• a kidney transplant
• dialysis, which removes waste and extra fluid from the blood
• supportive care

If you're being treated for chronic kidney disease, your doctors may need to change other medicines you are on. This is because many medicines can affect the kidneys, such as blood pressure drugs and anti-inflammatory medicines. Some medicines which leave the body through the kidneys may need to have their dose changed.

Lifestyle measures

Chronic kidney disease will gradually get worse, but there is plenty you can do to slow the progression and improve your quality of life.

Eating a healthy diet is important.

• Eat a variety of whole fresh seasonal foods.
• Limit processed foods and sugar.
• Limit salt to less than 5g a day (too much salt can increase blood pressure).
• Limit your intake of saturated and trans fats.

In the later stages of chronic kidney disease, you may need to follow specific instructions from your doctor on what you can eat or drink.

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

• Aim for 150 to 300 minutes of moderate physical exercise or 75 to 150 minutes of vigorous physical activity each week.
• Make sure you do some muscle strengthening exercises.

Other changes you should make include:

• stop smoking
• limit alcohol to less than 2 standard drinks a day
• maintain a healthy weight — if you have chronic kidney disease, you should ideally have a BMI (body mass index) of 25 or less

Can chronic kidney disease be prevented?

There is plenty you can do to help keep your kidneys healthy.

• Watch your weight — being overweight increases your risk of diabetes and high blood pressure, which in turn increase your risk of kidney disease.
• Eat healthily — a diet high in fruit and vegetables and low in salt, sugar and fats is best.
• Drink plenty of water — avoid sugary drinks (such as soft drinks).
• Exercise regularly.
• Do not smoke.
• Limit your alcohol intake to less than 2 standard drinks a day.
• Find ways to help you relax and reduce stress.
• Be aware of your risk factors — if you know you are at risk of kidney disease, you can have your kidneys checked regularly.

What if I am at high risk for kidney disease

People with diabetes and people with high blood pressure have a higher risk of getting kidney disease.

If you have diabetes, it's very important to keep your blood sugar level under control. You should also have your doctor check your blood pressure regularly.

Your doctor should also check your cholesterol and make sure that any urinary tract infections (UTIs) are treated straight away.

Complications of chronic kidney disease

Kidney disease can cause many different problems, including:

• fluid retention (which could lead to swelling in your arms and legs, high blood pressure, or fluid in your lungs)
• pericarditis (swelling in the sac around your heart)
• an increase in potassium levels in your blood
• anaemia

It can also cause:

• heart disease
• weak bones and an increased risk of bone fracture (breaking)
• damage to your central nervous system, which can cause difficulty concentrating, personality changes or seizures (fits)
• lowered immune response (making you more vulnerable to infection)
• pregnancy complications

Resources and support

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

Kidney Health Australia also has resources for Aboriginal and Torres Strait Islander peoples.

You can read about diabetes and kidney health on the Diabetes Australia website.