Urine Albumin-Creatinine Ratio (ACR)

Early kidney damage (diabetes)

This test compares the amount of albumin, a protein, with the amount of creatinine, a waste product, in a single urine sample. Healthy kidneys let very little albumin into the urine, so a raised ratio is one of the earliest signs of kidney damage. Using a ratio corrects for how concentrated or dilute the urine is, so a spot sample can be used instead of a full day's collection.

• As a regular check for early kidney damage in people with diabetes
• To screen for kidney damage in people with high blood pressure
• To follow chronic kidney disease and see whether protein loss is changing
• To help assess heart and blood vessel risk, as albumin in the urine is linked to higher risk

Eating and drinking as usual is fine. The first urine of the morning is preferred. Avoid hard exercise the day before, and tell your doctor if you have a fever, a urine infection or your period, because these can raise albumin for a short time.

Sample

Urine sample

How it works

You collect the urine in the sterile container provided: pass the first part into the toilet, catch the middle part in the container and close the lid tightly. A trained collector labels the sample and takes it to the laboratory.

Report

Within 24 hours of collection.

Your report shows the albumin-creatinine ratio against the laboratory's reference range. A raised ratio can point to early kidney damage, often linked to diabetes or high blood pressure, but short-term causes such as infection, fever or heavy exercise can also raise it. Because it varies from day to day, a raised result is usually repeated before any conclusion is drawn. Your doctor will interpret it with your blood tests and history.

One test: Urine Albumin-Creatinine Ratio (ACR), from one urine sample.