Urine Albumin Creatinine Ratio Explained
What a uACR result in mg/mmol actually means, the sex-specific Australian cut-offs, the everyday things that push a result up temporarily, and how it pairs with your eGFR.
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The Quick Answer
The urine albumin creatinine ratio (uACR, or just urine ACR) measures how much albumin is leaking out of your blood and into your urine. Healthy kidney filters hold albumin back almost completely, so finding more than a trace suggests those filters are letting protein through. Australian labs report it in mg/mmol.
Australian cut-offs are sex specific. Normal is generally below 2.5 mg/mmol in men and below 3.5 mg/mmol in women, with the difference coming from the fact that men excrete more creatinine, which sits on the bottom of the ratio. Above those figures the result falls into the moderately increased band, and above roughly 25 mg/mmol in men or 35 mg/mmol in women into the severely increased band.
One high result is not a diagnosis. Albuminuria has to be persistent, confirmed on at least two of three samples over about three months, before it counts towards chronic kidney disease. Infections, exercise, fever and menstrual blood all push a single result up, which is why the repeat test carries more weight than the first one.
Why a Ratio Instead of Just the Albumin Level
Urine concentration swings enormously through the day. Drink two litres of water and everything in your urine is diluted. Go six hours without a drink on a hot day and the same amount of albumin appears far more concentrated. An albumin concentration on its own would therefore tell you as much about your fluid intake as about your kidneys.
Creatinine solves that problem. Your muscles release creatinine into the blood at a fairly steady rate, and your kidneys clear it into urine at a fairly steady rate, so creatinine concentration in a urine sample is a reliable marker of how concentrated that sample is. Dividing albumin by creatinine cancels out the dilution effect, and what is left reflects the rate of albumin leak.
Why the 24 hour collection fell out of use
Collecting every drop of urine for a full day used to be the reference method. It is inconvenient, frequently done incompletely, and a missed void invalidates the whole collection. A spot ACR gives comparable information from one sample, so Australian practice moved to it for routine screening and monitoring.
Why mg/mmol and not mg/g
Australia reports the ratio in milligrams of albumin per millimole of creatinine. United States laboratories report milligrams per gram, and the numbers are roughly nine times larger for the same result. A figure of 30 mg/g in an American article corresponds to about 3.4 mg/mmol here, which is worth knowing before comparing your report to overseas advice.
Australian Reference Bands, and the A1 to A3 Categories
Australian reports usually give sex-specific cut-offs. International kidney guidelines also group albuminuria into three categories, A1 to A3, using single thresholds of 3 and 30 mg/mmol for everyone. Both appear in Australian practice, which is why the same result can be described in two different ways. Exact cut-offs vary a little between Sonic, Healius, Australian Clinical Labs, Dorevitch, Laverty, QML, Capital Pathology, SA Pathology and PathWest, so the reference interval on your own report is the one that counts.
Normal to mildly increased
Only a trace of albumin is reaching the urine, which is what healthy kidney filters do. In someone with a risk factor for kidney disease, this result is repeated at the recommended screening interval rather than forgotten, because albuminuria can develop later.
Moderately increased (previously microalbuminuria)
More albumin is leaking than expected. This is the range that matters most for early detection, because it often appears years before eGFR starts to fall and while the underlying cause is still very treatable. It needs confirming on repeat samples before it counts as persistent.
Severely increased (previously macroalbuminuria)
A substantial protein leak. This level is associated with a higher risk of kidney function declining over time and of cardiovascular events, and it usually prompts closer monitoring, a search for the specific cause, and consideration of nephrology referral.
Nephrotic range
A very heavy protein leak, roughly equivalent to more than three grams of protein in the urine per day. Often accompanied by swelling of the ankles and around the eyes, a low blood albumin and raised cholesterol. This picture warrants prompt specialist kidney assessment.
See where your own ACR sits against these bands
Upload your pathology report and SmarterBlood will place your uACR in the right band for your sex, line it up with your eGFR and creatinine, and chart how the ratio has moved across every report you have.
Upload Your ResultsWhat Pushes a Result Up Temporarily
These are the reasons a single raised ACR so often comes back normal on repeat. Check the list against the day you gave the sample before assuming the result reflects your kidneys.
Urinary tract infection
Inflammation in the bladder or kidney allows albumin into the urine independently of any filter damage. An infection also usually shows white cells, nitrites or blood on the same sample. The ACR is normally repeated once the infection has been treated and settled.
Vigorous exercise in the previous 24 hours
Strenuous exercise transiently increases albumin excretion, sometimes substantially. A gym session, a long run or a hard game the day before the sample can push an otherwise normal result into the moderately increased band. Laboratories and GPs commonly advise avoiding heavy exercise for a day before the test.
Fever or any acute illness
A febrile illness raises albumin excretion temporarily. Collecting the sample while acutely unwell is one of the most common avoidable reasons for a misleadingly high result, and repeating once well is the standard response.
Menstruation or visible blood in the sample
Blood contains albumin, so contamination from menstrual bleeding, or from any visible blood in the urine, inflates the ratio. The sample is usually deferred until bleeding has finished.
Poorly controlled blood pressure or blood glucose
A period of high blood pressure or high blood glucose increases albumin leak while it lasts. Here the raised result is genuine rather than artefactual, but it can improve once control is regained, which is why the test is repeated rather than acted on once.
Decompensated heart failure
Fluid overload and the circulatory changes of worsening heart failure raise albuminuria. The kidneys and the heart influence each other closely, and treating the cardiac problem often lowers the ratio.
Upright posture and a late-in-the-day sample
Albumin excretion rises when you are upright and active, so an afternoon sample reads higher than a first morning void in the same person. This is why the first morning sample is preferred, particularly for borderline results.
A very high protein meal or dehydration
Both can nudge the result. Dehydration concentrates the urine, and while dividing by creatinine corrects for most of that effect, extremes at either end still add noise to a borderline result.
Confirming Persistent Albuminuria
Two of three samples over about three months
Australian practice treats albuminuria as persistent when at least two out of three samples, collected over roughly three months, sit above the cut-off. That definition exists because the biological variation in albumin excretion from one day to the next is large, and because a single result carries real consequences if it is used to label someone with chronic kidney disease. Three months is long enough to let a temporary cause pass and short enough not to delay treating a genuine problem.
Keep the collection conditions the same
Comparing a first morning sample against an afternoon sample introduces a difference that has nothing to do with your kidneys. Using the first urine passed after waking each time, and avoiding heavy exercise the day before, makes the three results genuinely comparable. If a first morning sample is impractical, tell the collector, so the result is interpreted with that in mind.
Why a normal dipstick does not close the question
A urine dipstick measures total protein and is relatively insensitive at low levels, so it frequently reads negative in someone whose laboratory ACR is clearly in the moderately increased band. That is the whole reason the ACR is the recommended screening test in Australia. If a dipstick was negative but the laboratory ACR is raised, trust the laboratory result.
How ACR and eGFR Grade Kidney Health Together
Your eGFR estimates how much filtering capacity remains. Your ACR shows whether the filters are leaking. Kidney health is graded on both at once, using eGFR categories G1 to G5 alongside albuminuria categories A1 to A3. The grid below summarises the risk grouping used in Australian kidney guidance. A normal eGFR with a raised ACR still carries increased risk, which is the single most useful thing this table shows.
eGFR 90 or above mL/min/1.73m2
A1 (normal ACR): Not CKD unless other kidney damage present
A2 (moderately increased): Moderate risk
A3 (severely increased): High risk
eGFR 60 to 89 mL/min/1.73m2
A1 (normal ACR): Not CKD unless other kidney damage present
A2 (moderately increased): Moderate risk
A3 (severely increased): High risk
eGFR 45 to 59 mL/min/1.73m2
A1 (normal ACR): Moderate risk
A2 (moderately increased): High risk
A3 (severely increased): Very high risk
eGFR 30 to 44 mL/min/1.73m2
A1 (normal ACR): High risk
A2 (moderately increased): Very high risk
A3 (severely increased): Very high risk
eGFR 15 to 29 mL/min/1.73m2
A1 (normal ACR): Very high risk
A2 (moderately increased): Very high risk
A3 (severely increased): Very high risk
eGFR Below 15 mL/min/1.73m2
A1 (normal ACR): Very high risk
A2 (moderately increased): Very high risk
A3 (severely increased): Very high risk
If your eGFR is also flagged low on the same report, start here:
Low eGFR ExplainedWho Should Have a Urine ACR, and How Often
The Australian Kidney Health Check combines three things: blood pressure, eGFR from a blood test, and urine ACR. Chronic kidney disease is usually silent until it is advanced, so the check is offered on the basis of risk factors rather than symptoms. Intervals below are the general pattern in Australian guidance; your GP sets yours.
Type 2 diabetes
From diagnosis, then at least annually. Kidney damage can be present at the point diabetes is first diagnosed, because the condition is often silent for years beforehand.
Type 1 diabetes
Generally from around five years after diagnosis, then at least annually.
High blood pressure
Every one to two years as part of a Kidney Health Check, more often if albuminuria has already been found or blood pressure is not at target.
Aboriginal and Torres Strait Islander adults
Annually from young adulthood, reflecting a substantially higher burden of kidney disease and the benefit of finding it early.
Established cardiovascular disease
Every one to two years. Albuminuria predicts cardiovascular events as well as kidney events, so the result informs heart risk too.
Family history of kidney failure
Every one to two years, earlier and more often where an inherited kidney condition is known in the family.
Obesity or current smoking
Every one to two years as part of a Kidney Health Check, since both independently raise the risk of chronic kidney disease.
Aged over 60
Every one to two years. Kidney function declines gradually with age, and albuminuria adds information that eGFR alone does not provide.
Very High Results and the Nephrotic Pattern
Most raised ACR results sit in the moderately increased band and are managed by a GP without any urgency beyond arranging the repeat test. A much higher result behaves differently. A ratio above roughly 220 mg/mmol corresponds to more than about three grams of protein lost per day, which is described as the nephrotic range.
Losing that much protein depletes albumin in the blood, and low blood albumin lets fluid move out of the circulation into the tissues. The recognisable combination is heavy albuminuria, a low serum albumin, swelling of the ankles and puffiness around the eyes, and raised cholesterol. Underlying causes include several forms of glomerular disease and advanced diabetic kidney disease, and they are distinguished by specialist investigation rather than from the ACR alone.
For the wider set of blood tests used to assess the kidneys:
Blood Tests for Kidney DiseaseWhen to Seek Urgent Care
Visible blood in the urine, or urine the colour of cola or tea
Blood from the kidney alongside albuminuria can indicate active inflammation of the kidney filters, which needs assessment within days rather than at the next routine appointment. Contact your GP promptly.
New swelling of the ankles, legs, or puffiness around the eyes
Swelling with heavy protein loss suggests a nephrotic pattern, where blood albumin has fallen enough to shift fluid into the tissues. This needs same-day or next-day medical review.
Passing much less urine than usual, or almost none
A sudden drop in urine output can indicate acute kidney injury. Seek urgent medical assessment rather than waiting for a repeat test.
Breathlessness at rest, or breathlessness when lying flat, alongside swelling
Fluid building up in the lungs needs urgent assessment. Go to an emergency department or call 000 if breathing is difficult.
Confusion, drowsiness, persistent vomiting or hiccups with a known low eGFR
These can be signs of advanced kidney failure and need emergency assessment.
Frothy urine that has appeared recently, with a very high ratio on the report
Persistent frothing can accompany heavy protein loss. On its own it is not an emergency, but with a nephrotic-range result it should be reviewed promptly rather than left to the next scheduled visit.
What Your GP Will Do Next
Exclude a temporary cause
Before anything else, your GP checks whether the sample was taken during an infection, a fever, menstruation or after heavy exercise. A urine microscopy and culture is often added to the same sample to look for infection and for red cells.
Repeat on a first morning sample
A raised ratio is confirmed on one or two further first morning samples, generally over about three months. Persistent albuminuria means at least two of three samples raised. A single result is not used to diagnose chronic kidney disease.
Check kidney function on blood tests
Creatinine and eGFR are measured alongside the urine test, together with electrolytes. The combination of eGFR and ACR is what grades kidney health, and either can be abnormal while the other looks fine.
Look for the driver
Blood pressure is measured properly, HbA1c or fasting glucose checks for diabetes, and lipids are reviewed. Diabetes and high blood pressure account for the majority of albuminuria in Australian general practice, and both are modifiable.
Review medications and other contributors
Regular non-steroidal anti-inflammatory use, some other medications, and conditions such as obstructive sleep apnoea and gout all feature in a full assessment. Your GP goes through the whole list rather than treating the number in isolation.
Consider imaging and further tests
A kidney ultrasound is arranged when the cause is unclear, when blood is present in the urine, or when an obstruction or structural problem is possible. Autoimmune and myeloma screening tests are added in selected cases.
Discuss kidney protective treatment
Where albuminuria is confirmed, your doctor will discuss options that reduce it and protect kidney function over time, including blood pressure targets and specific medication classes used for this purpose. Which of these suits you is a decision for your doctor, taking your other conditions into account.
Set a monitoring schedule and consider referral
Confirmed albuminuria is monitored on a defined schedule so the trend can be tracked. Referral to a nephrologist follows Australian guidance based on the level of albuminuria, the eGFR, the rate of change, and blood pressure control.
Sources and reference ranges
Adult reference ranges on this page follow the AACB and RCPA harmonised reference intervals unless stated otherwise; the range printed on your own report always takes precedence because laboratories differ.
- healthdirect Australia: kidney function tests
- Pathology Tests Explained (Australasian Association for Clinical Biochemistry and Laboratory Medicine)
- Australasian Association for Clinical Biochemistry and Laboratory Medicine, publisher of the harmonised reference intervals
- healthdirect Australia: full blood count
Urine Albumin Creatinine Ratio: Frequently Asked Questions
What does the urine albumin creatinine ratio measure?
The urine albumin creatinine ratio, usually shortened to uACR or urine ACR, measures how much albumin is leaking from your blood into your urine. Albumin is a protein that healthy kidney filters hold back almost completely, so finding more than a trace in urine suggests the filters are letting protein through. The result divides the albumin concentration by the creatinine concentration in the same sample, which corrects for how dilute or concentrated your urine happens to be. Australian laboratories report the ratio in milligrams of albumin per millimole of creatinine, written mg/mmol. Reporting a ratio rather than a raw albumin level is what makes a single random urine sample useful, instead of requiring a full 24 hour urine collection.
What is a normal urine albumin creatinine ratio in Australia?
Australian reference ranges are sex specific, because men naturally excrete more creatinine than women, which shifts the ratio down. A result below about 2.5 mg/mmol in men and below about 3.5 mg/mmol in women is generally reported as normal. Between roughly 2.5 and 25 mg/mmol in men, or 3.5 and 35 mg/mmol in women, is the moderately increased range, historically called microalbuminuria. Above about 25 mg/mmol in men or 35 mg/mmol in women is the severely increased range, historically called macroalbuminuria. Laboratory cut-offs differ slightly between providers, so the reference interval printed on your own report always takes precedence over any general figure.
Does one high urine ACR result mean I have kidney disease?
No. A single raised result is a reason to repeat the test, not a diagnosis. Chronic kidney disease requires albuminuria to be persistent, which in Australian practice means at least two of three samples raised over a period of around three months. A great many single high results turn out to be temporary, caused by a urinary tract infection, vigorous exercise in the day before the sample, a fever, menstrual blood in the sample, or an episode of poorly controlled blood pressure or blood glucose. Your GP will usually ask for a repeat first morning sample once any of those has settled, before drawing any conclusion about your kidneys.
Why does the laboratory want a first morning urine sample?
The first urine passed after waking is the preferred sample because it removes most of the day to day noise. Albumin excretion rises with upright posture and with physical activity, so a sample collected in the afternoon after a normal day of walking around can read higher than the same person would read first thing in the morning. Using the first morning void consistently also makes repeat results directly comparable, which matters when the whole point of repeating the test is to see whether the level is genuinely persistent. If a first morning sample is not practical, a random sample is still informative, and your GP will simply interpret a borderline result with more caution.
How do urine ACR and eGFR work together?
They measure two different things and neither replaces the other. The eGFR from your blood test estimates how much filtering capacity your kidneys still have. The urine ACR shows whether the filters that remain are leaking. Kidney health is graded on both at once, which is why Australian kidney guidelines use a colour coded table combining eGFR categories with albuminuria categories. Someone can have a completely normal eGFR and a raised ACR, and still be at increased risk of losing kidney function later and of cardiovascular events. That combination is one of the main reasons the urine test is requested alongside blood tests rather than instead of them.
How often should I have a urine ACR test?
Frequency depends on your risk. The Australian Kidney Health Check combines blood pressure, eGFR and urine ACR, and is generally recommended every one to two years for adults with a risk factor, which includes hypertension, established cardiovascular disease, obesity, smoking, a family history of kidney failure, and being aged over sixty. Annual testing is usual for people with diabetes and for Aboriginal and Torres Strait Islander adults. Once albuminuria has been confirmed, testing becomes more frequent, because the trend in the ratio over time is used to judge whether kidney health is stable, improving or deteriorating. Your GP sets the interval for your own situation.
Can a high urine albumin creatinine ratio come down again?
Yes, and a falling ratio is one of the clearest signs that whatever is driving the leak is being addressed. Better blood pressure control, better blood glucose control in diabetes, weight reduction, stopping smoking and treating an underlying condition can all reduce albuminuria, sometimes back into the normal range. Certain medications used for blood pressure and for kidney protection are prescribed partly because they lower the ratio. None of that is something to start or change on your own, and the decision belongs with your doctor, but it does mean a raised result is worth acting on rather than accepting as fixed.
Is a urine ACR the same as protein on a urine dipstick?
They are not the same, and the difference matters. A dipstick detects total protein and is relatively insensitive, so it commonly reads negative in people whose laboratory ACR is clearly in the moderately increased range. That is why a normal dipstick does not exclude early kidney damage, and why the ACR is the recommended test for kidney screening in Australia rather than dipstick protein. A urine protein creatinine ratio, or uPCR, is a separate laboratory test that measures all protein rather than albumin specifically. It has a role in some kidney conditions, but it is less sensitive than the ACR for picking up early diabetic kidney damage.
When does a raised urine ACR need a kidney specialist?
Australian kidney guidelines point towards nephrology referral in several situations rather than for any raised result. These include a ratio in the severely increased range, a ratio above about 30 mg/mmol alongside a declining eGFR, an eGFR below 30, a sustained fall in eGFR of a quarter or more from baseline, blood in the urine that appears to come from the kidney rather than the bladder alongside albuminuria, and blood pressure that stays high despite three medications. A ratio in the nephrotic range, generally taken as above roughly 220 mg/mmol, particularly with swelling and a low blood albumin, warrants prompt specialist assessment. Your GP decides on referral using your full picture.
Related Reading
Got Your Kidney Results?
Upload your pathology report and SmarterBlood's AI will read your urine ACR alongside your eGFR, creatinine and electrolytes, in plain English with Australian reference ranges, and chart the ratio across every report so you can see the trend.
This page provides general educational information about the urine albumin creatinine ratio. It is not a substitute for professional medical advice, diagnosis, or treatment. Only your GP, with your blood pressure, eGFR and full medical history in front of them, can tell you what your result means, whether it needs repeating, and what monitoring or treatment applies to you. SmarterBlood does not provide medical care.