When you think about kidney tests, you may immediately think about creatinine or eGFR. But there is another important measurement that can provide valuable information about kidney health: protein in the urine.
Your kidneys are designed to filter waste and extra fluid from your blood while keeping important substances, including proteins, in your bloodstream. When albumin—a major blood protein, appears in the urine in higher-than-expected amounts, it may be a sign that the kidney's filtering system is not working normally. This is called albuminuria, also known as proteinuria.
Why Is Protein Normally Kept Out of Urine?
Your kidneys contain millions of tiny filtering structures called glomeruli.
These filters allow waste and excess substances to leave the bloodstream while keeping important components of the blood inside.
Albumin is one of those important proteins.
When the kidney's filtering barrier becomes damaged, albumin can begin passing into the urine. This makes urine albumin an important marker of kidney damage.
Protein in the Urine May Not Cause Symptoms
One reason albuminuria can go unnoticed is that many people don't feel any different.
A person can have increased urine albumin without experiencing obvious kidney-related symptoms. That is why laboratory testing is so important, particularly for people who have risk factors for kidney disease.
In some cases, people may notice foamy urine or swelling around the eyes, feet, ankles or abdomen, but these signs are not present in everyone.
What Is a UACR Test?
One of the commonly used tests for detecting albumin in urine is the urine albumin-to-creatinine ratio (UACR).
A UACR measures the amount of albumin in relation to creatinine in a urine sample. It is commonly performed using a single urine specimen and is useful for identifying and monitoring kidney damage.
A UACR:
- Below 30 mg/g is generally considered within the normal range.
- Above 30 mg/g is considered abnormal and may indicate increased albumin in the urine.
However, one abnormal result does not automatically mean that someone has chronic kidney disease.
An Abnormal Result Does Not Always Mean Permanent Kidney Damage
Albumin levels can temporarily increase for several reasons.
These can include:
- Dehydration
- Intense physical activity
- Fever
- Infection
- Certain changes in health conditions
Because temporary factors can influence urine albumin, healthcare professionals may repeat testing to determine whether the elevation persists.
This is one reason why interpreting a kidney test requires more than simply looking at a single number.
Diabetes and High Blood Pressure Matter
Some of the most important risk factors for kidney disease are diabetes and high blood pressure.
Both conditions can damage the kidney's filtering structures over time. Monitoring urine albumin can therefore be particularly important for people who have these conditions.
NIDDK identifies urine albumin and eGFR as key markers used to identify and monitor chronic kidney disease.
Why Should You Track Your Results?
Kidney health is not determined by one number.
Healthcare professionals may look at both:
eGFR — an estimate of how well the kidneys are filtering blood.
UACR — an indicator of how much albumin is present in the urine.
Looking at these measurements together can provide a more complete picture of kidney health and help clinicians monitor changes over time.
For people already living with CKD, changes in urine albumin can also help healthcare professionals assess how the condition is responding to treatment and monitor its progression.
What Can Help Protect Kidney Health?
There isn't one action that protects everyone's kidneys in exactly the same way. Your care plan should be based on your individual health.
Depending on your circumstances, kidney-protective care may include:
- Keeping blood pressure under control
- Managing diabetes and blood glucose
- Following an appropriate eating plan
- Staying physically active
- Avoiding tobacco
- Taking medications as prescribed
- Attending recommended follow-up appointments
- Monitoring kidney function and urine albumin when appropriate
Your healthcare provider can help determine which steps are appropriate for you.
Don't Ignore the Quiet Signs
Kidney disease can develop without obvious symptoms, which makes routine testing especially valuable for people who are at increased risk.
If you have diabetes, high blood pressure, cardiovascular disease or a family history of kidney failure, ask your healthcare provider whether kidney function and urine albumin testing are appropriate for you.
Understanding your kidney numbers can help you have more informed conversations about your health.
Kidney Care at Blanchard Nephrology
Your kidney health involves more than a single laboratory result.
At Blanchard Nephrology, our goal is to provide thoughtful, comprehensive kidney care while helping patients understand their kidney health and the factors that may affect it.
If you have questions about your kidney function, urine test results or risk of kidney disease, speak with your healthcare provider about the appropriate next steps.
Blanchard Nephrology
655 Fox Run Rd, Suite C
Findlay, OH 45840
567-525-3163
