How to track your urine albumin (UACR) over time
The urine albumin-to-creatinine ratio, UACR or just ACR, is the kidney test that can show damage while eGFR is still in the normal range. It is checked every year in diabetes, and it is half of how kidney disease is staged.
It is also one of the noisiest tests you can track. Two samples a week apart can differ a lot with nothing having changed. That is why no guideline acts on a single result, and why a history of results, collected the same way, is worth far more than any one of them.
What the test measures
Albumin is the most common protein in blood. Healthy kidney filters hold almost all of it back, so very little reaches the urine. When the filters are damaged, by diabetes, high blood pressure, or other kidney disease, more albumin gets through. Albumin in the urine is called albuminuria.
The test uses a single urine sample. The lab measures two things in it:
- Urine albumin, as a concentration, usually in mg/L.
- Urine creatinine, a waste product your muscles make at a fairly steady rate.
Then it divides one by the other. The result is the albumin-to-creatinine ratio.
Why the ratio, not just the albumin
How concentrated a urine sample is depends on how much you drank. The same albumin loss reads high in a concentrated morning sample and low in a dilute one after a lot of water. The KDIGO 2024 chronic kidney disease guideline explains that because creatinine passes into the urine at a fairly constant rate through the day, dividing by it corrects for how concentrated the urine is and reduces the swing between samples. KDIGO asks labs to report the ratio, not the albumin concentration alone.
So if your report shows both a urine albumin in mg/L and a ratio in mg/g, the ratio is the one to track. A urine albumin concentration on its own is hard to compare from one sample to the next. If your report has the albumin and creatinine but no ratio, the UACR calculator works it out in mg/g and mg/mmol.
“Microalbumin”
You will often see this test called microalbumin, or microalbumin/creatinine ratio. It is the same albumin, not a smaller kind. The name comes from “microalbuminuria”, the old term for albumin in the range of 30 to 300 mg/g. The American Diabetes Association’s Standards of Care now call that range moderately elevated albuminuria, “formerly microalbuminuria.” Labs still use the old names, which is one reason a UACR history can end up split across several test names.
The numbers on the report
In the United States, UACR is reported in mg/g, meaning milligrams of albumin per gram of creatinine. Many other countries use mg/mmol. KDIGO gives the conversion:
mg/mmol = mg/g × 0.113 (or mg/g = mg/mmol × 8.84)
KDIGO grades albuminuria in three categories, and they are the same at every lab:
| Category | mg/g | mg/mmol | Description |
|---|---|---|---|
| A1 | Below 30 | Below 3 | Normal to mildly increased |
| A2 | 30 to 300 | 3 to 30 | Moderately increased |
| A3 | Above 300 | Above 30 | Severely increased |
The table is easy to over-read:
- A3 at 300 mg/g is 30 mg/mmol, not 300. If your history includes results from abroad, a 30 is either normal or severely increased depending on the unit. Keep the unit with every result. The lab unit converter handles this and other common conversions.
- It is a continuous measure. The ADA notes that differences within the normal and abnormal ranges are linked to kidney and heart outcomes. A rise from 8 to 25 mg/g is still “normal”, and still worth seeing.
- The categories describe persistent albuminuria. One result above 30 is a reason to repeat the test, not a diagnosis.
- Sex and body size move it. KDIGO notes that women and people with low body weight excrete less creatinine, which gives a higher ratio for the same albumin loss. Men and people with higher body weight tend to read lower.
Half of kidney staging
KDIGO stages chronic kidney disease by two numbers: eGFR, graded G1 to G5, and albuminuria, graded A1 to A3. Someone with an eGFR of 70 and a UACR of 400 is at higher risk than someone with an eGFR of 55 and a normal UACR. An eGFR of 60 to 89 counts as kidney disease only when there is other evidence of damage, and albuminuria is the most common one. How to track your eGFR over time covers the other half, and the eGFR calculator can recalculate older results on the current equation.
How the sample is collected
UACR is measured on a spot urine sample, not a 24-hour collection. KDIGO prefers a first morning void, the first urine after you get up, because it tracks 24-hour albumin loss well, varies less from day to day, and rules out orthostatic proteinuria, protein that appears in the urine only when upright. KDIGO estimates it affects 2% to 5% of adolescents. A random sample is acceptable when a first morning one is not available, and KDIGO suggests confirming a random result of 30 mg/g or more with a later first morning sample.
In practice, many results in your history will be random samples taken at a clinic visit. That is fine. It is one more thing to note, since a first morning sample and an afternoon sample are not quite the same measurement.
How often it is tested
- Diabetes: the ADA recommends UACR and eGFR at least once a year in everyone with type 2 diabetes, and in type 1 diabetes once it has lasted five years or more. How to track your A1c over time covers the other yearly number.
- Known chronic kidney disease: the ADA recommends UACR and eGFR 1 to 4 times a year depending on the stage. KDIGO recommends more frequent testing for people at higher risk of progression, or when the result will change treatment.
- High blood pressure and other risks: KDIGO supports screening people at high risk, including those with high blood pressure and heart disease.
- On a kidney-protective medicine: the ADA notes that continued testing shows the response to treatment as well as any progression.
What counts as a real change
UACR varies a lot between samples. The ADA puts the biological variation in urine albumin at more than 20% between measurements, and notes that UACR varied even when measured weekly over one month. Its conclusion is that repeated measurements and tracking the trend over time are needed to follow UACR properly.
That is the reason for the confirmation rule. The ADA says two of three samples collected within 3 to 6 months should be abnormal before anyone is considered to have moderately or severely elevated albuminuria.
For changes over time in someone with kidney disease, KDIGO’s rule of thumb is that a doubling of UACR on a later test is beyond the usual lab variability and worth a closer look. It also notes that in large population studies, a doubling within two years went with a 50% to 100% higher risk of kidney failure. A rise from 40 to 55 mg/g is within the noise. A rise from 40 to 90 is not.
Going the other way, reductions matter too. The ADA notes that in trials of ACE inhibitors and ARBs in type 2 diabetes, getting UACR below 300 mg/g, or lowering it by more than 30% from baseline, was associated with better kidney and heart outcomes. An analysis of 28 cohorts and nearly 700,000 people found that a 30% fall in UACR over two years was associated with about a 17% lower risk of kidney failure, more so in people who started higher.
A few questions help sort it out:
- Were both samples collected the same way? First morning or random, and not during one of the situations below.
- Is the change bigger than your usual spread? If your results have bounced between 20 and 45, a 38 is not news. A 120 is.
- Did it hold? One high result followed by two ordinary ones is the pattern the two-of-three rule exists for.
- Did eGFR move too? A rising UACR with a falling eGFR is a different picture from either one alone.
Things that move UACR
Several things raise UACR for a while without meaning your kidneys have changed. The ADA lists:
- Exercise in the past 24 hours
- Infection and fever
- Heart failure
- Very high blood sugar
- Menstruation
- Very high blood pressure
KDIGO adds blood in the urine, and notes that a symptomatic urinary tract infection can add protein from the infection itself. Blood from a period can get into the sample, which is why the cycle post suggests scheduling urine tests for a week when you are not bleeding.
The creatinine half of the ratio can move too. KDIGO notes that high protein intake or exercise raise creatinine in the urine, which pulls the ratio down, while a low-protein diet or acute kidney injury lowers urine creatinine and pushes the ratio up. A big change in diet or muscle mass can nudge your results without any change in albumin.
None of these mean the result is wrong. They mean it needs a note next to it, and often a repeat sample.
Medications that lower it
Lowering albuminuria is one of the goals of treatment, so for many people on these drugs a falling UACR is the expected result:
- ACE inhibitors and ARBs. KDIGO recommends one of these for people with kidney disease and albuminuria with diabetes, and for severely increased albuminuria without diabetes. The ADA says they should be titrated to get UACR as low as possible, since risk persists while it stays raised.
- SGLT2 inhibitors, such as empagliflozin and dapagliflozin.
- Finerenone, a nonsteroidal mineralocorticoid receptor antagonist. The ADA notes that for both SGLT2 inhibitors and finerenone, most of the kidney benefit is mediated by the fall in albuminuria.
- GLP-1 receptor agonists, which the ADA lists among treatments that lower albuminuria.
Starting one of these drugs gives you a before-and-after to read. The drop in UACR is the point of the drug, and the ADA describes ongoing testing as a way to see the response. ACE inhibitors, ARBs, and SGLT2 inhibitors also often cause an expected dip in eGFR in the first weeks, covered in the eGFR post. Seeing both on one timeline keeps that dip from looking like damage. Did the medication actually do anything? covers reading before-and-after results fairly, and with a test this noisy, two results on each side are better than one.
What to record with each result
For each UACR result, keep:
| Field | Why |
|---|---|
| Collection date | Spacing matters for the two-of-three rule and for trends. |
| Value and unit | mg/g or mg/mmol. They differ by a factor of almost 9. |
| Which number | The ratio, or the albumin concentration alone (mg/L). Track the ratio. |
| Sample type | First morning or random. |
| eGFR from the same visit | The other half of kidney staging. |
| Medications | Starts, stops, and dose changes, with dates. ACE inhibitors, ARBs, SGLT2 inhibitors, finerenone, GLP-1 RAs. |
| Recent exercise | A hard workout in the 24 hours before can raise the result. |
| Other context | Fever, infection or UTI, period, very high blood sugar or blood pressure. |
UACR goes by many names: Albumin/Creatinine Ratio, Microalbumin/Creatinine Ratio, Microalb/Creat Ratio, Urine ACR, and Albumin, Urine, among others. Some of those are the ratio and some are the albumin concentration alone. Merge the ratio names into one series, keep the concentration on its own line, and never combine the two.
Charting it
A few choices make a UACR chart honest:
- Space points by date. A confirmation sample a month later and a yearly check should not look evenly spaced.
- Draw lines at 30 and 300 mg/g, the category cutoffs, rather than relying on a printed range alone.
- Expect scatter. A zigzag from 25 to 45 and back is normal for this test. Read the level over several results, not the last step.
- Think in ratios, not differences. Going from 20 to 40 is a doubling. So is 200 to 400. If your tool offers a log scale, it shows both the same size.
- Mark medication changes, and look for the drop afterward.
- Put eGFR on the same timeline.
How to track your lab results over time has the general method for any test.
Tracking UACR in HealthViewer
HealthViewer is a lab results tracker that runs on your own computer. It imports urine albumin results from lab report PDFs, MyChart downloads, and direct connections to your health system. Results from a direct connection file the ratio as “Albumin/Creatinine Ratio (Urine)” and the albumin concentration alone as “Microalbumin (Urine)”, as separate tests. Urine creatinine has its own line, “Creatinine (Urine)”.
Ratio names from PDFs, such as “Microalb/Creat Ratio”, may land as their own tests. In the Test Catalog, use Merge… to combine the ratio names into one series. Merge ratio with ratio only.
Urine albumin concentrations in mg/L and mg/dL are converted to share one chart. The ratio is not converted between mg/g and mg/mmol. If your history mixes the two, results in the unit that cannot be converted are left off the chart and listed under it, rather than plotted on the wrong scale.
The built-in Kidney tag covers BUN, creatinine, eGFR, and creatinine clearance, but not the urine tests. Add the Kidney tag to your UACR in the Test Catalog and it joins them in the Trends filter. The overlay view puts UACR and eGFR on one chart, and medication markers show where an ACE inhibitor, ARB, SGLT2 inhibitor, or finerenone started. You can also set a custom range of 0 to 30 mg/g in the Test Catalog, and Trends shades it with a Custom range label.
If your lab reports urine albumin and urine creatinine but not the ratio, you can
calculate it in Settings → Derived Tests. Create
a formula A / B, with A as Microalbumin (Urine) in mg/L and B as Creatinine (Urine)
in g/L, a date window of 0 so both come from the same day, and “No unit” as the
result unit. Results in other units, such as creatinine in mg/dL, are converted first,
and the result is the ratio in mg/g. Put the unit in the name, for example “UACR
mg/g”, since the result is stored without one.
A journal note on the day of a hard workout, a fever, or a UTI shows up on the chart when you turn on journal markers, so an odd result keeps its explanation.
Everything stays in an encrypted file on your computer, with no account and no cloud service. Getting Started walks through the first import.
This post is general information, not medical advice. Talk to your clinician about what your UACR means for you and before starting, stopping, or changing any treatment.