Urine “Microalbumin” Test in Diabetes: How Often Should It Be Checked?

What this test is actually checking

The “microalbumin” urine test is usually the UACR (urine albumin‑to‑creatinine ratio). It checks for tiny amounts of protein leakage (albumin) into the urine.

In diabetes, this can be an early sign of diabetic kidney damage, often years before creatinine rises or symptoms appear.

Frothy urine can happen for many reasons, but persistent protein leakage is one important cause. That is why doctors use UACR instead of guessing.

How often should a person with diabetes do UACR and eGFR?

Most major guidelines recommend checking kidney status at least once a year using:

• UACR - urine albumin‑to‑creatinine ratio (spot urine sample).

• eGFR - estimated glomerular filtration rate (from a blood creatinine test).

Typical timing used in practice

• Type 2 diabetes

  • Start screening from the time of diagnosis.

  • Then at least annually thereafter.

• Type 1 diabetes

  • Start screening after 5 years of diabetes duration (because clinically significant kidney disease is rare in the first few years).

  • Then at least yearly.

If UACR is abnormal, or if kidney risk is higher (long diabetes duration, high BP, rising creatinine, known CKD), doctors often check more often than once a year (for example, 2-4 times/year depending on CKD stage).

What number is “normal” and what is “high”?

UACR is usually reported as mg/g (or sometimes mg/mmol).

International KDIGO albuminuria categories:

• A1 - Normal to mildly increased:

  • UACR <30 mg/g (<3 mg/mmol)

• A2 - Moderately increased (“microalbuminuria” in older terms):

  • UACR 30-300 mg/g (3-30 mg/mmol)

• A3 - Severely increased (“macroalbuminuria”):

  • UACR >300 mg/g (>30 mg/mmol)

These categories help estimate kidney and cardiovascular risk and guide how closely someone should be monitored and treated.

If it is positive once, does it mean permanent kidney damage?

Not always.

UACR can be temporarily elevated due to:

• Urinary tract infection.

• Fever or recent acute illness.

• Heavy or vigorous exercise in the previous 24 hours.

• Markedly high blood sugars or very high blood pressure at the time of the test.

Because of this, guidelines advise that albuminuria should be confirmed as “persistent”:

• Usually by repeating UACR 1-2 more times over several months.

• Persistent elevation in at least 2 out of 3 samples (after ruling out infection and other acute factors) supports a diagnosis of diabetic kidney disease.

A single abnormal result should not be used alone to label someone with permanent kidney damage.

If UACR stays high, what does it mean for the future?

Persistent albumin in urine is an important risk marker:

• Higher chance of kidney disease progression over time.

• Higher cardiovascular risk (heart attack, stroke, heart failure) even when eGFR is still normal.

The good news:

• Early detection, combined with:

  • Good glucose control

  • Good blood pressure control

  • Use of kidney‑protective medicines when appropriate (ACE inhibitors/ARBs, SGLT2 inhibitors, etc.). can substantially slow kidney damage and reduce cardiovascular risk.

So a positive UACR is a “warning flag”, not the end of the story.

Simple takeaway patients remember

• UACR is an early warning test for diabetic kidney stress.

• For most people with diabetes:

  • Do UACR + eGFR at least once every year, and

  • More often if results are abnormal or CKD is already present.

A normal UACR today is reassuring - but staying on schedule with yearly checks and good control gives the best protection for the kidneys.