Your kidneys are just as important to your health as other organs of your body such as your heart and lungs. Most people are born with two kidneys. They sit under your ribcage – one on each side of your spine (back bone). Each kidney is about the size of a fist.

Why are the kidneys so important?

Your kidneys do many important jobs to keep you healthy. They:

• filter waste and extra water from your blood, making it into urine (wee)
• balance the amount of water, salt and other minerals in your body
• help keep your blood pressure at normal levels
• make a hormone that helps make red blood cells. Red blood cells carry oxygen around your body and give you the energy you need
• help keep your bones strong and healthy.

This video from Kidney Health Australia explains how your kidneys work and how to check your kidney health:

^{Source: Kidney Health Australia, Understanding Kidney Disease video. November 2020. Date accessed 14 June 2022}

Chronic kidney disease means your kidneys are not working as well as they should and/or show signs of damage. Chronic means the disease is present for 3 months or more.

When your kidneys aren’t working properly, wastes build up in your body. It can also lead to other health problems, such as high blood pressure, heart attack and stroke.

Finding it early gives you the best chance to have the right treatment. This can slow down or even stop the disease from getting worse and lower your chance of other health problems.

How common is it?

Chronic kidney disease is usually caused by other conditions.

Diabetes (high levels of glucose, a type of sugar, in your blood) is the most common cause of kidney failure (where the kidneys are not working well enough to keep you alive) in Australia, affecting nearly 4 out of 10 cases. This rate is even higher for Aboriginal and Torres Strait Islander peoples, with nearly 7 out of 10 cases of kidney failure caused by diabetes. High levels of glucose in your blood from diabetes can damage your kidneys.

High blood pressure can also damage the parts of your kidneys that filter waste from your blood.

Many other conditions can cause kidney failure, such as infections or inflammation of the kidneys (nephritis).

Linking chronic kidney disease, diabetes and cardiovascular disease

Cardiovascular disease includes diseases of the heart and blood vessels (veins and arteries). It includes heart attack, heart failure and stroke (when your brain can’t get the blood supply it needs, usually because of a blood clot or sudden bleed).

• These conditions share many of the same risk factors, like smoking, having high blood pressure and being very overweight.

• Actions you can take to keep your kidneys healthy, such as healthy eating, quitting smoking and taking your medicines, will also help the health of your heart and blood vessels, and diabetes.

^{Source: Kidney Health Australia. My Kidneys My Health: Living with early stage chronic kidney disease. Kidney Health Australia, 2015}

• Having high blood pressure increases your chance of kidney disease, heart attack and stroke.
• Kidney disease can cause high blood pressure.
• Having diabetes increases your chance of kidney disease, heart attack and stroke.

Learn more about diabetes here or from Diabetes Australia. The Heart Foundation has information about heart disease. Find out more about stroke from the Stroke Foundation.

Most people with chronic kidney disease do not notice any symptoms, especially in the early stages. Less than 1 in 10 people with chronic kidney disease know they have it.

Your kidneys can lose 90% of their normal activity before you feel unwell.

But finding it early gives you the best chance to slow or stop the disease from getting worse. A Kidney Health Check can help you and your doctor find out how well your kidneys are working.

See your doctor for a Kidney Health Check if you:

• have diabetes
• have high blood pressure
• have heart disease (eg, heart attack, heart failure), stroke or blood vessel disease (narrowing in veins and arteries causes reduced blood flow, often in your legs and feet)
• have family members with kidney failure (where the kidneys are not working well enough to keep you alive. People with kidney failure need dialysis or a kidney transplant to stay alive.)
• are obese (very overweight)
• are a smoker or have ever been a smoker
• have had acute kidney disease (where an illness or injury causes loss of normal kidney activity for less than 3 months)
• are of Aboriginal or Torres Strait Islander origin aged over 30 years.

The way to know how well your kidneys are working is to have three simple tests:

^{Adapted with permission from Kidney Health Australia: Chronic Kidney Disease (CKD) Management in Primary Care (4th edition). Kidney Health Australia, 2020.}

1. A blood test checks how well your kidneys are working. It will tell your doctor what your estimated glomerular filtration rate (eGFR) is. eGFR is a measure of how well your kidneys are working. A low eGFR means your kidneys are not working as well as they should. If it is below a specific level for more than 3 months this may mean you have chronic kidney disease.
2. A urine (wee) test checks for signs of kidney damage. Healthy kidneys are like tight filters that allow fluid to pass out but keep protein and blood cells in. Damaged kidneys become leaky and let blood and proteins pass into your urine. Finding a protein called albumin in your urine can be an early sign of kidney damage. This is called albuminuria. A urine test called the albumin:creatinine ration (ACR) shows whether you have albumin in your urine. If it is above a specific level for more than 3 months this may mean you have chronic kidney disease.
3. Checking your blood pressure: High blood pressure and chronic kidney disease are strongly connected. Each one can cause the other to develop.

Learn more about these tests in the fact sheets from Kidney Health Australia.

Ask your doctor if a Kidney Health Check is right for you.

If your blood and/or urine tests are abnormal (eGFR is too low and ACR is too high) for at least 3 months, you have chronic kidney disease.

Your doctor may then do more tests to find out what is causing kidney damage. These can be:

• an ultrasound to see what your kidneys look like
• blood tests to check for other conditions
• a urine microscopy, where your doctor looks at a sample of your urine under a microscope.

Together, these tests help complete your diagnosis of chronic kidney disease. Knowing the cause makes it clearer which treatment can best help you.

Your doctor might also refer you to a nephrologist (a specialist kidney doctor).

The good news is that the earlier you find out you have chronic kidney disease, the quicker you can start doing things to slow down or stop the disease from getting worse. Getting the right treatment also protects against other health problems, like heart and blood vessel disease, and stroke.

Your treatment will depend on how well your kidneys are working, as well as your heart and blood vessel health and if you have other conditions like diabetes. Your doctor will work with you to make a plan to help you stay as healthy as possible.

• To help you understand what’s involved in a Kidney Health Check, ask your doctor these questions from Kidney Health Australia:
  • Why is a Kidney Health Check important?
  • What will the result of a Kidney Health Check tell me?
  • What is a normal result?
  • After my Kidney Health Check – what are the next steps?
  • Do I need to change my lifestyle? (eg, diet, activity, weight, smoking)
  • Where can I find out more about kidney disease?

• Kidney Health Australia gives information and support to people living with kidney disease:
  • Visit kidney.org.au
  • Call the Kidney Helpline on 1800 454 363
  • The My Kidneys My Health handbook and app helps you understand kidney disease and what you can do.

• NPS MedicineWise can help you learn about chronic kidney disease:
  • Visit Kidney health: looking after your kidneys
  • Call the Medicines Line for information about your medicines 1300 MEDICINE (1300 633 424).