Quick links onsite: Risk Factors and Symptoms I Prevention I Kidney Glossary
Kidney disease occurs when the nephrons inside your kidneys, which act as blood filters are damaged. This leads to the build up of waste and fluids inside the body.
Why are your kidneys so important?
Kidneys are the silent partner to good health! We can live quite well with only one kidney and indeed, some people live a healthy life even though born with one missing.
Our kidneys are amazing, they play a major role in maintaining your general health and wellbeing but are not usually thought of as essential to a healthy life.
But while bones can break, muscles can waste away and the brain can sleep without risk to life, if both kidneys fail, as happens in end stage kidney failure, bone, muscle or brain can not carry on.
What can go wrong with your kidneys?
Kidney disease is called a ‘silent disease’ as there are often no warning signs. More often kidney function worsens over a number of years. This is good news, because if kidney disease is found early, medication, dietary and lifestyle changes can increase the life of your kidneys and keep you feeling your best for as long as possible.
- You can lose up to 90 per cent of kidney function without realising it, by which time it is almost impossible to prevent further serious problems.
- People can live a near normal life with as little as 20 percent of their total kidney function.
- When symptoms do occur the initial signs may be general, such as feeling tired or generalised itching.
- As kidney disease progresses, the symptoms can include changes in the urine (reduced volume, discolouration, blood or pus), nausea and vomiting, and appetite loss.
- Other symptoms include swollen or numb hands and feet (because of water retention), weakness and lethargy, darkened skin and muscle cramps.
View: How our kidneys work and take the test at Check My Kidneys to find out your risk of kidney disease.
Download education posters Are you at risk? and publication Kidney Disease: Are you one in three?
Kidney disease is a life-threatening condition and should not be ignored!
CKD is a long term health condition that in many cases is preventable. Early detection and treatment can help prevent kidney failure and the need for dialysis or transplant treatment.
- Acute Kidney Failure is sometimes kidney failure which can happen quickly, caused for example by a sudden loss of large amounts of blood, infection, or an accident. A sudden drop in kidney function is often short lived but can occasionally lead to lasting kidney damage.
- Chronic Kidney Disease (CKD) is responsible for substantial burden of illness and premature mortality. If you lose over 1/3 of your kidney function for over 3 months, it is called Chronic Kidney Disease (CKD). Sometimes kidney disease leads to kidney failure, which requires dialysis or a kidney transplant to keep you alive. As kidney function decreases, waste begins to build-up in the blood.
Professor Alan Cass - George Institute's Renal & Metabolic Division presents A closer look at kidney disease
This video covers what kidneys do in our bodies - to how we can prevent kidney disease
How can I avoid kidney disease?
You can reduce your risk of kidney disease especially if you are at increased risk:
- become a non-smoker
- ensure your blood glucose is well controlled if you have diabetes
- control your blood pressure
- stay fit, exercise regularly and maintain a healthy weight by eating a healthy diet
- avoid high salt foods and reduce salt intake wherever you can
- drink water - instead of sugary drinks
- drink alcohol moderately (no more than 2 standard glasses a day for men -1 standard glass for women)
WHAT ARE THE STAGES OF CHRONIC KIDNEY DISEASE?
Test results or clinical values can be grouped to show how well your kidneys are working. These groupings are only a guide and results may be outside these ranges. Kidney function may naturally fall as we age. Other factors can also lower kidney function normally.
Kidney function can be classified into stages, depending on your eGFR. Your doctor uses these stages as a guide for deciding which treatment is best for you. Treatment also depends on the cause of your kidney damage. Controlling diabetes and high blood pressure can help to slow or prevent further kidney damage. It also reduces the risk of other health problems, such as heart attacks and strokes.
Stage 1: A normal GFR greater than or equal to 90 mL/min/1.73m2
Stage 2: Slightly decreased GFR between 60‐89 mL/min/1.73m2
If your kidney function is at stage 1 or 2, you only have CKD if you have albuminuria, haematuria, a pathological abnormality or a structural abnormality.
Stage 3a: Mild‐moderate decrease in GFR between 45‐59 mL/min/1.73m2
Stage 3b: Moderate‐severe decrease in GFR between 30‐44 mL/min/1.73m2
Stage 4: Severe decrease in GFR between 15-29 mL/min/1.73m2
Stage 5: Kidney failure as GFR decreases to less than 15 mL/min/1.73m2 or dialysis is started
Your eGFR and albuminuria results are combined to provide an overall picture of how well your kidneys are working. Your doctor uses this information to decide which treatment is best for you. Treatment also depends on the cause of your kidney damage. Controlling diabetes and high blood pressure can help to slow or prevent further kidney damage. It also reduces the risk of other health problems, such as heart attacks and strokes.
COMMON KIDNEY RELATES TESTS AND PROCEDURES
People with kidney disease undergo a large range of medical tests and procedures. Medical tests are an important part of making an action plan to meet your health care needs. They are needed to confirm a diagnosis, plan treatment or check progress. Some of the most commonly used tests for people with kidney disease are outlined here. Also see Kidney Glossary to find out meanings of terms used in tests.
Tests for kidney function and damage
- Estimated Glomerular Filtration Rate (eGFR) - The best measure of your kidney function. It shows how well your kidneys are cleaning the blood. Your GFR is usually estimated (eGFR) from the results of the creatinine blood test.
eGFR is reported in millilitres per minute per 1.73m2 (mL/min/1.73m2)
A GFR of 100 mL/min/1.73m2 is in the normal range so it is useful to say that 100 mL/min/1.73m2 is about equal to ‘100% kidney function’
A GFR of 50 mL/min/1.73m2 could be called ‘50% kidney function’
- Creatinine - A waste product made by the muscles. It is usually removed from the blood by the kidneys and passes out in the urine. When the kidneys aren’t working well, creatinine stays in the blood. Creatinine varies with age, gender and body weight so is not an accurate way of measuring overall kidney function. When on dialysis creatinine levels are always high.
- Urea - A waste product, which is made as the body breaks down protein. High urea levels suggest decreased kidney function.
- Albumin Creatinine Ratio – Used to measure the amount of albumin (a kind of protein) that leaks into your urine when your kidneys are damaged. A small or ‘micro’ amount of albumin in the urine is called microalbuminuria, and a larger ‘macro’ amount is called macroalbuminuria
- Urinalysis - An examination of a urine sample to detect medical conditions like kidney and liver disease, diabetes and urinary tract infections. This can be a visual examination for colour and clearness. For example, blood in the urine (haematuria) may make urine red or an infection can make it cloudy. A chemically treated strip or dipstick is used to test for pH, sugar (glucose), blood, bacteria or waste products. A urine sample can be sent to a laboratory for an examination under a microscope or to grow a culture if an infection is suspected.
Blood tests for diabetes
- Glucose - Blood glucose monitoring is a measurement of glucose (sugar) in the blood. Values can vary depending on physical activity, meals and insulin administration. Your glucose level is raised in diabetes.
- Glycosylated haemoglobin (HbA1c) - A test that measures the amount of glycosylated haemoglobin in the blood. Glycosylated haemoglobin is a molecule in red blood cells that attaches to glucose (blood sugar). There are higher levels of glycosylated haemoglobin if you have more sugar in your blood.
Tests for heart health
- Blood pressure - The pressure of the blood against the walls of the arteries as the heart pumps the blood around your body. Blood pressure is recorded as two numbers, for example 140/90 mmHg. The larger number indicates the pressure in the arteries as the heart squeezes out blood during each beat. This is called the systolic blood pressure. The lower number indicates the pressure as the heart relaxes before the next beat. This is called the diastolic blood pressure.
Blood tests - Cholesterol
- Cholesterol - A naturally-occurring, waxy substance made by the body. It is an essential building block of cell membranes, hormones and vitamin D. Too much cholesterol in the blood can cause clogging of the arteries and lead to heart disease.
- Low-density lipoprotein (LDL) cholesterol - Known as the “bad” cholesterol. The higher the amount of LDL cholesterol, the higher the risk of heart disease.
- High-density lipoprotein (HDL) cholesterol - Known as the “good” cholesterol. The higher the amount of HDL cholesterol, the lower the risk of heart disease.
- Triglycerides - the most common type of fat stored in your body. A high level of triglycerides in your blood can increase your risk of heart disease.
Blood tests for vitamin and mineral levels
- Potassium (K+) - A mineral found in many foods. If your kidneys are healthy, they remove extra potassium from the blood. If your kidneys are damaged, the potassium level can rise and affect your heart. A low or high potassium level can cause an irregular heartbeat.
- Sodium (salt, Na+) - A substance which together with chloride makes up common salt. High levels of sodium may indicate dehydration.
- Calcium (Ca) - Needed for healthy bones and teeth. Most of the cells in the body need calcium to work properly. Raised calcium levels may cause headaches, nausea, sore eyes, aching teeth, itchy skin, mood changes and confusion.
- Phosphate (PO4) – A mineral, which together with calcium keeps your bones strong and healthy. Too much phosphate causes itching and pain in the joints, such as the knees, elbows and ankles. When the kidneys are not functioning properly, high levels of phosphate accumulate in the blood
- Vitamin D - A vitamin that is made in your skin after you have been in the sun. The kidneys change Vitamin D so that your body can use it.
Tests for anaemia
- Haemoglobin (Hb) - The oxygen-carrying part of red blood cells that gives them their red colour and transports oxygen around the body.
- Haematocrit (Hct) - A measure of the percentage of blood made up of red blood cells.
- Transferrin saturation (TSAT) - Indicates the proportion of the iron-transporting protein transferring and helps to determine if the body is transporting or binding iron in the right way.
- Ferritin - A protein that stores iron in your body.
Tests for hormones
Quick links onsite: Kidney Health Resources I Recommended external weblinks
- X‐rays ‐ Uses very short energy beams to produce an image of body parts such as bones and organs.
- Ultrasound - Examination of the kidneys, prostate or bladder using sound waves to outline the structure of organs.
- Computerised Tomography (CT) Scan or Magnetic Resonance Imaging (MRI) - These tests use multiple small X-ray beams, or radio-frequency wavelengths and a strong magnetic field to provide clear and detailed pictures of internal organs and tissues. You may be asked to swallow a liquid containing a positive contrast material or ‘dye’, which allows the radiologist to see the kidneys more clearly.
- Kidney biopsy ‐ A procedure where a needle is passed through your skin into the kidney and a small piece of kidney tissue is removed for examination under a microscope. Local anaesthetic is used and it is a relatively painless procedure.
- Fistulagram - Used to check fistula function. Dye is injected into your fistula to allow its structure to show up on an x‐ray.
- Cystoscopy ‐ This test uses a thin, flexible, tube-like telescope called a cystoscope to view the inside of the bladder and some parts of the kidney.
- Intravenous Pyelogram (IVP) - Series of x‐rays of the abdomen taken after dye has been injected into a vein in the arm. The dye is then viewed on the x-ray pictures as it passes through the kidneys
Updated 25 February 2014
Disclaimer: Information provided is intended as an introduction to this topic and not meant to substitute for your doctor's or health professional's advice. All care is taken to ensure this information is relevant and applicable to each Australian state. Kidney Health Australia recognises each person's experience is individual and variations do occur in treatment and management due to personal circumstances. Consult a healthcare professional for specific treatment recommendations.