One in 3 Australians is at increased risk of developing kidney disease!

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.

Stage 1:  A small amount of kidney damage, but GFR is often normal.
Kidney function is between 50–100% of normal - which is a GFR greater than 90 mL/min.

Stage 2:  Mild kidney damage, so there is a slight drop in GFR to between 60–89 mL/min. A small amount of kidney damage, although GFR may be normal

• Often there are no symptoms in the early stages of kidney disease, blood tests can be normal.
• There may be scarring and blockages that change blood flow to parts of the kidney so they don't work as well as they should.
• There is an increased risk of heart disease. You doctor can help you reduce your risk of heart disease.

Stage 3:  Moderate kidney damage so blood pressure increases. CKD can be diagnosed as GFR falls to 30-59 mL/min. Sometimes discovered because the level of waste product in the blood rises.

• Some people begin to feel unwell and notice an increase in urine frequency.
• Blood pressure can rise as the kidneys slow down. High blood pressure further increases the risk of heart disease, heart attack and stroke.
• Early signs of bone disease may be present.
• Anaemia may appear, caused when there are not enough red blood cells in the blood to carry oxygen around the body.
• Symptoms include weakness, fatigue and a shortness of breath.

Stage 4:  Severe kidney damage and GFR is very low at 15-29 mL/min.

• High blood pressure almost always occurs.
• You may start to notice changes in the amount of urine you pass.
• Lack of energy, increased tiredness and reduced appetite are common symptoms.
• You may need to make dietary changes, including limiting the use of salt or reducing the amount of potassium or phosphorus in your diet.

Stage 5:  Kidney failure occurs and GFR is less than 15 mL/min

• The kidneys are only functioning at 10-15 per cent of their capacity and are unable to properly filter waste products, remove extra water from the body and help maintain the blood's chemical balance.
• This is the time to consider commencing dialysis or having a kidney transplant.
• The results of your blood tests to evaluate your kidney function are called clinical values.

What do your kidney tests results mean?

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. The normal level for blood or serum creatinine is less than 120μmol/L for males and 90μmol/L for females. A blood test helps to work out how quickly your kidneys remove or ‘clear’ creatinine from the blood. Creatinine is a good measure of kidney function as it does not change with diet. However it does vary with age, gender and body weight so is not an accurate way of measuring overall kidney function.

Glomerular Filtration Rate (GFR) - is the best measure of your kidney function and helps decide the stage of kidney disease. It shows how well your kidneys are cleaning the blood. GFR is reported in millilitres per minute. Your GFR is usually worked out from the results of the creatinine blood test with your age and gender. Your GFR helps the doctor plan your treatment. A normal GFR is greater than 90 mL/min. See eGFR fact sheet.

• Percent of kidney function - is an estimate of the level that each kidney is working. A GFR of 100 millilitres per minute (mL/min) is in the normal range so it is useful to say that 100 mL/min is about equal to ‘100% kidney function’. A GFR of 30 mL/min could be called ‘30% kidney function’.

Haematuria or blood in the urine - occurs when red blood cells leak into the urine. It can turn urine a red or dark cola colour, which is visible to the eye or may only be found by a urine test, which is called microscopic haematuria. Blood in the urine is a common sign of urinary tract infections but can be the first sign of a problem with the kidneys or the bladder.

Microalbuminuria - can mean that your kidneys are damaged so albumin, a kind of protein, leaks into the urine in very small or ‘micro’ amounts. Microalbumin in the urine is often an early warning of kidney disease but can also be present for other reasons. The level can be measured by a special urine test either on a single urine sample or timed urine collection. Normal values on this test are less than 15 to 30 mg/l. A microalbumin test should be done at least yearly if you have diabetes.

Proteinuria - occurs when there are abnormal levels of protein in the urine. Normally, protein is not removed when the kidneys filter waste from the blood. However, when the kidneys are damaged protein leaks through the damaged filters and leaves in the urine, along with the waste. The appearance of protein in the urine may be the first sign of an otherwise silent kidney condition.

Potassium - is 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. 

Urea - is a waste product made by the body as it uses protein from the food you eat such as meat. You need protein for every day growth, building muscles and repairing tissue. If you have lost some kidney function, your kidneys may not be able to remove all the urea from your blood.