A urine protein-creatinine ratio (UPCR) test looks for high levels of protein in your urine, which can happen in kidney disease. Results that are higher than average may be a sign of a kidney-related issue.
A urine protein-creatinine ratio (UPCR) test is a diagnostic tool used to help diagnose and monitor kidney disease.
It’s done by collecting a urine sample and then analyzing its protein-to-creatinine ratio by dividing the concentration of protein by the concentration of creatinine.
Creatinine is a waste product made in your muscles. It’s eventually filtered out by your kidneys and excreted from your body in urine. Proteins can be present in urine, but they’re normally only found at low levels.
A UPCR test looks for proteinuria, which is when protein levels in your urine are higher than normal. Proteinuria may be a sign of an underlying health condition that can require medical treatment,
Keep reading to learn more about what to expect during a UPCR test, when you might need it, and normal levels.
A doctor may order a UPCR test to assess the function of your kidneys if you’re experiencing symptoms of kidney disease, such as:
- edema (fluid retention)
- shortness of breath
- fatigue
- dry, itchy skin
- more frequent urination
- foamy urine
A UPCR test can also be used to monitor the severity of kidney disease and assess how effectively your treatment plan is managing your chronic kidney disease.
Normally, little protein is present in your urine. Because proteins are important for your body’s health and function, your kidneys typically don’t filter them out of your bloodstream.
However, when the filtering ability of your kidneys is impaired, they become less effective at maintaining the balance of proteins in the body. This means that more protein is filtered into your urine.
As such, proteinuria can be a sign that you have problems with your kidneys. The level of proteinuria is
Connect with a primary care doctor if you experience any symptoms of kidney disease, as they can order a UPCR test and other tests to help detect any underlying health conditions.
A 2020 review notes that there’s some variation in the cutoffs for different levels of proteinuria. Test results can also be given in different units or no units at all, depending on the lab.
The Kidney Disease: Improving Global Outcomes 2012 Clinical Practice Guidelines define three categories of proteinuria as follows:
- normal to mildly increased
- moderately increased
- severely increased
The table below shows the values for each category of proteinuria when measured using a UPCR test.
| Normal to mildly increased | Moderately increased | Severely increased | |
|---|---|---|---|
| UPCR in mg/mg | less than 0.15 | 0.15 to 0.50 | greater than 0.50 |
| UPCR in mg/mmol | less than 15 | 15 to 50 | greater than 50 |
| UPCR in mg/g | less than 150 | 150 to 500 | greater than 500 |
What does it mean if your levels are outside of the normal range?
A result on the UPCR test that’s higher than normal may be an indication of kidney disease. Kidney disease is often caused by the effects that other health conditions have on your kidneys,
- diabetes
- high blood pressure
- heart disease
- kidney stones
- autoimmune diseases, such as lupus
- cancers, such as kidney cancer and multiple myeloma
- rare inherited conditions, such as polycystic kidney disease
It’s also important to note that other, more benign factors can also lead to proteinuria and, therefore, a higher result on a UPCR test. This includes:
- dehydration
- stress
- vigorous physical activity
- having an acute illness or infection
UPCR in pregnancy
A doctor
Preeclampsia affects up to 1 in 20 pregnancies. Symptoms may include persistent headache, vision changes, and upper abdominal pain.
The UPCR cutoff for preeclampsia is a value of 0.3 milligrams per milligram (mg/mg) or higher. This can also translate to values of:
- 30 milligrams per millimole (mg/mmol) or higher
- 300 milligrams per gram (mg/g) or higher
Typically, a urine sample for a UPCR test is collected in the morning, shortly after waking up. This is because the urine is more concentrated, allowing even small amounts of protein and other substances to be detected.
A healthcare professional will provide you with a container to collect a urine sample in the bathroom. They will also provide you with instructions on how to do this properly and the amount you need to collect.
To collect a urine sample, you may have to:
- Wash your hands with soap and water.
- Open the container without touching the inside.
- Urinate for 3 seconds in the toilet, stop the flow, then continue in the container until you collect the required amount.
- Stop the flow, then finish urinating in the toilet.
- Close the container, then wash your hands.
- Return the sample to the healthcare professional.
How do I prepare for a UPCR test?
There’s no specific preparation required for a UPCR test. But it’s important to tell the doctor if you’re menstruating or have bleeding hemorrhoids, as blood and other discharge may affect the results of your urine sample.
What should I expect after a test?
After providing your urine sample, the doctor may analyze it there using a dipstick. In this case, they will provide your results within a few minutes.
In other cases, they will send your urine sample to a laboratory for a more detailed analysis. In this case, your doctor may take up to 10 days to contact you with the test results.
If the values of your UPCR test are outside of the normal range, a doctor may want to order additional tests to evaluate your kidney function. This may include:
- additional urine tests, such as urinalysis, 24-hour urine sample, and urine albumin-creatinine ratio (UACR)
- blood tests to determine the amounts of creatinine, urea, and electrolyte levels, and estimated glomerular filtration rate (eGFR)
- imaging tests, such as a kidney ultrasound or CT scan
- kidney biopsy
A high protein-to-creatinine ratio may be a sign of an underlying health condition that could affect your kidney function, such as diabetes, kidney disease, and heart disease.
Some ways to help lower your creatinine levels may include drinking more water, limiting protein and sodium intake, avoiding creatine supplements, and increasing fiber intake.
A UPCR test result of 2.5 or more is a sign of very severe proteinuria.
A UPCR test can help a doctor determine if you have high levels of protein in your urine. It’s done using a urine sample collected at a single point in time.
Results are calculated by dividing the concentration of urine protein by the concentration of urine creatinine. UPCR values that are higher than normal can be a sign of kidney disease.
The UPCR test is only one test of your kidney function. If you receive a higher-than-normal value on a UPCR test, a doctor will do other tests to get a better idea of how your kidneys are working.