If your doctor believes you may be at risk for kidney damage or kidney disease, it’s likely that you’ve had or will have a microalbuminuria test. The microalbuminuria test is a urine test that measures the amount of albumin in your urine. Albumin is a protein that your body uses for cell growth and to help repair tissues. It’s normally present in the blood. A certain level of it in your urine may be a sign of kidney damage.
Your kidneys are responsible for removing waste products from the blood and regulating the water fluid levels in your body. Healthy kidneys make sure that waste is filtered out from your body and that nutrients and proteins that are essential to your health, such as albumin, stay in your body.
It’s important to make sure your kidneys are functioning properly so that albumin remains in your blood. If your kidneys have been damaged, they may not be able to keep albumin in your blood and it will start to spill into your urine. When this occurs, you may experience a condition known as albuminuria. Albuminuria simply means that your urine contains albumin.
The microalbuminuria test is also known as the albumin-to-creatinine ratio (ACR) test or the urine albumin test.
Your doctor may recommend a microalbuminuria test if you’re at risk for kidney damage or if they suspect your kidneys might be damaged. It’s important for your doctor to test and diagnose you as early as possible if your kidneys are damaged. Treatment may delay or prevent kidney disease. The two most common causes of kidney disease in the United States are diabetes and hypertension, or high blood pressure. Your doctor may order the microalbuminuria test if you have one of these conditions.
The purpose of the microalbuminuria test is to measure the amount of albumin in the urine. The test is typically used in conjunction with a creatinine test to provide an albumin-to-creatinine ratio. Creatinine is a waste product in the blood that your kidneys should remove. When kidney damage occurs, creatinine levels in the urine decrease while albumin levels may increase.
How often you need microalbuminuria tests depends on whether you have any underlying conditions or whether you have the symptoms of kidney damage. Early stages of kidney damage usually show no signs or symptoms. However, if kidney damage is extensive, your urine may appear foamy. You may also experience swelling, or edema, in your:
The American Diabetes Association recommends an annual microalbuminuria test for people between the ages of 12 and 70 that have been diagnosed with type 1 or type 2 diabetes. Diabetes can cause damage to the kidneys. Your doctor can use a microalbuminuria test to detect this damage. If you have positive test results and you have diabetes, your doctor should confirm the results through additional testing over a three- to six-month period. If they confirm you have kidney damage, your doctor will be able to treat the kidney injury and help improve and maintain your kidney function.
High blood pressure
If you have high blood pressure, your doctor may also screen you for kidney damage using the microalbuminuria test. High blood pressure can cause damage to the vessels of the kidney, resulting in the release of albumin into the urine. Testing for albumin should occur at regular intervals. Your doctor will determine when you need this test.
The microalbuminuria test is a simple urine test. You can eat and drink normally before the test. No special preparation is necessary for this test.
Several types of microalbuminuria urine tests are available:
Random urine test
You can take a random urine test at any time. Doctors often combine it with a creatinine test to improve the accuracy of the results. You can have this test in any healthcare setting. You’ll collect the sample in a sterile cup, and your doctor will send it to a laboratory for analysis.
24-hour urine test
For this test, you’ll need to collect all of your urine for a 24-hour period. Your doctor will provide you with a container for urine collection that you must keep in the refrigerator. Once you’ve collected your urine for 24 hours, you’ll need to return the sample to your healthcare provider for lab analysis.
Timed urine test
Your doctor may ask you to provide a urine sample first thing in the morning or after a four-hour period of not urinating.
Once the lab reports the results, your doctor will be able to provide you with more information about the results and what they mean.
The microalbuminuria test only requires normal urination. This test has no risks, and you shouldn’t have any discomfort.
According to the National Kidney Foundation, albuminuria is the presence of too much albumin in the urine. Microalbuminuria is the presence of a slightly high level of protein in the urine, and macroalbuminuria is the presence of a very high level of albumin in the urine each day. Results of the microalbuminuria test are measured as milligrams (mg) of protein leakage in your urine over 24 hours. Results generally indicate the following:
- Less than 30 mg of protein is normal.
- Thirty to 300 mg of protein is known as microalbuminuria, and it may indicate early kidney disease.
- More than 300 mg of protein is known as macroalbuminuria, and it indicates more advanced kidney disease.
Several temporary factors can cause higher-than-normal urinary microalbumin results, such as:
- blood in your urine, or hematuria
- a fever
- recent vigorous exercise
- a urinary tract infection
Certain medications can also affect albumin levels in your urine. Examples include:
- antibiotics, including aminoglycosides, cephalosporins, penicillin, polymyxin B, and sulfonamides
- antifungal medications, including amphotericin B and griseofulvin
- lithium, which is a medication people use to treat the manic episodes of bipolar disorder
- penicillamine, which is a medication people use to treat rheumatoid arthritis
- phenazopyridine, which is a medication people use to treat urinary tract pain
- salicylates, which are medications people use to treat arthritis
- tolbutamide, which is a medication people use to treat diabetes
Once your results have been processed, your doctor will call you and may want to test your urine again if the first test has abnormal results. If necessary, your doctor will recommend the best treatment options for your kidney damage and its underlying cause.
Measuring the amount of albumin in your urine is important for detecting the presence of kidney damage. Kidney damage can lead to kidney disease or failure. If kidney failure occurs, dialysis is often necessary. By identifying kidney damage before it results in kidney failure, your doctor can slow the progression of any further damage and help preserve your kidney function over the long term.