Understanding Albuminuria and Albumin Urine Test- Pathology

Medically Reviewed by Dr. Sony Sherpa (MBBS) 

The urine albumin test allows you to check your urine for the protein albumin. Albumin does not pass through healthy kidneys and into your urine. However, the protein may begin to show up in urine samples if your kidneys are diseased or damaged.

You may have to provide a urine sample to your doctor during a visit. A one-time sample taken at home or over a certain length of time, such as over 4 hours or 24 hours, may also be requested by your doctor.

What Is Albumin?

Produced by the liver, albumin is a typical component of the blood that is filtered by the kidney. It keeps the pressure inside blood vessels stable by maintaining the intravascular oncotic pressure. Albumin also acts as a carrier protein for thyroid hormones, fatty acids, and steroids in the blood.

Understanding Albuminuria

A normally functioning kidney has no traces of albumin in the urine. Even if present, it is in minimal quantities, about 250mg in a day. Any damage to the kidney results in an unusual range of albumin entering the urine, far over the typical level. Albuminuria is the medical term for this condition.

If early kidney damage is not treated, more albumin may leak into the urine. Albumin leakage from the kidneys may indicate severe renal disease. As a result, chronic kidney disease may develop.

Kidney impairment brought on by diabetes is most frequently the cause of albuminuria. Yet, a variety of different illnesses can harm the kidneys.

What Is The Difference Between Albuminuria And Micro-Albuminuria?

The blood contains significant amounts of albumin. When there are kidney problems, it is one of the first proteins capable of passing through the kidneys and into the urine because of its small molecular size. This condition is known as micro-albuminuria. It is characterized by the presence of small amounts of albumin in the urine, which persistently remains abnormal. 

It is essential to highlight that some physiological conditions, such as an episode of exercise, may result in micro-albuminuria. Therefore, repeating it after a day or two of not exercising if your microalbumin urine level is elevated would be recommended.

As the kidney damage worsens, the amount of albumin in the urine rises. As a result, the condition's name changes from micro-albuminuria to macro-albuminuria (macro meaning large).

Causes Of Albuminuria

Your kidneys remove waste from your blood while preserving nutrients, such as proteins, that your body needs. Yet, certain illnesses and situations cause proteins to bypass your kidneys' filtering mechanisms, resulting in protein in the urine.

While not always indicative of kidney impairment, many conditions can temporarily increase the amount of protein in the urine. These conditions include:

• Exposure to extreme cold
• Dehydration
• Strenuous exercise
• Fever

Urine albumin tests are essential to diagnose and screen renal disorders and other issues affecting kidney function. These tests are also used to track the development of the disease and the impact of treatment. These conditions and diseases include the following:

• Chronic kidney disease
• Focal segmental glomerulosclerosis (FSGS)
• Diabetic nephropathy (kidney disease)
• Glomerulonephritis (Inflammation of kidney cells that remove waste from the blood)
• Berger's disease or IgA nephropathy (inflammation of the kidney brought on by an accumulation of the antibody immunoglobulin A)
• High blood pressure (hypertension)
• Lupus
• Nephrotic syndrome (damage to the kidneys' tiny filtering blood vessels)
• Preeclampsia
• Multiple myeloma

Protein in the urine can also be caused by other kidney problems and factors, such as:

• Amyloidosis (buildup of abnormal proteins in different organs)
• Certain medications, such as nonsteroidal anti-inflammatory drugs
• Heart failure
• Heart disease
• Hodgkin's lymphoma
• Kidney infection (pyelonephritis)
• Orthostatic proteinuria (Being upright causes the level of urine protein to increase.)
• Malaria
• Rheumatoid arthritis

What Are The Symptoms Of Albuminuria And Micro-Albuminuria?

Early on, there might not be any observable symptoms or indicators. However, swelling of the hands, feet, belly, and face may happen as kidney function diminishes and significant amounts of proteins are excreted in the urine. Albuminuria could cause irreversible kidney damage if it worsens. It might necessitate dialysis or a kidney transplant in some patients. Testing the urine is the only way to determine how much protein passes into the urine, symptoms or no symptoms.

Cardiovascular disease is associated with micro-albuminuria. In addition to kidney disease, damaged blood vessels might result in a stroke and heart failure.

Who Is At Risk For Albuminuria?

Proteinuria can occur in people with certain chronic illnesses, such as diabetes, hypertension, obesity, and certain renal conditions. A few such at-risk groups are as follows:

• Pacific Islander Americans
• American Indians
• African Americans
• Hispanic-Americans
• Individuals with a family history of kidney disease
• Older people
• Overweight people

What Is The Purpose Of The Albumin Urine Test?

This test is used to determine if a urine sample has an excessive level of the protein albumin. Kidney disease can be identified, screened for, and tracked using different types of urine albumin tests.

Diagnosis

This includes examinations or tests conducted by a doctor following the onset of symptoms. For example, the diagnostic process might consist of a urine albumin test if you notice any health changes that kidney disorders can bring.

Urinary abnormalities, such as frothy urine, variations in urine volume or frequency, and blood in the urine, are symptoms associated with kidney impairment. Kidney issues can also lead to abnormal swelling, itchiness, weariness, and appetite loss.

Screening

These tests are designed to look for health issues before symptoms show up, so treatment can begin before a disease has advanced. For example, urine albumin tests are frequently performed to diagnose signs of kidney problems because the early stages of kidney disease may not produce symptoms.

A urine albumin-to-creatinine ratio test is frequently used to check for albuminuria. If you have a higher risk of kidney diseases, such as high blood pressure, diabetes, or a family history of renal problems, this test is performed as part of a screening test. In addition, older adults and members of specific racial and cultural groups may benefit from screening.

An estimated glomerular filtration rate (eGFR) test, which evaluates how well the kidneys filter the blood, may be combined with a urine albumin test as part of a kidney disease screening.

Urine albumin testing may provide information for these disorders and any potential complications, as the presence of high or extremely high levels of albumin in the blood has also been linked to obesity, cardiovascular disease, and diabetes.

Monitoring

Urine albumin tests are also used to track kidney health over time. This frequently involves repeating urine albumin tests at regular intervals to monitor the course of renal disease or the efficacy of treatment.

When Should I Take This Test?

Urine testing for albumin can be applied in a variety of medical settings. These are typically performed for diagnosis if you exhibit any signs of possible kidney damage. Changes in the way you urinate, puffiness, and inexplicable itching are a few symptoms that may indicate kidney trouble. In these situations, testing for kidney function and urine albumin may be carried out.

Tests for urine albumin can be applied in a variety of medical settings. These are typically carried out if you exhibit any symptoms of potential kidney damage. Changes in your urine, puffiness of the face, and unexplained itching are a few symptoms that may indicate a kidney problem. Urine albumin and other renal function tests might be carried out in these cases.

An urine albumin test performed for screening is only recommended for some people. If you do not have risk factors for kidney disease, the negative aspects of this testing, such as the financial cost or possible follow-up, are thought to outweigh the positive aspects.

If you have diabetes, it is advised that you have urine albumin testing done. Furthermore, if you have type 2 diabetes, this testing may be done annually.

How To Prepare For Albumin Urine Test?

Your healthcare professional or the lab will provide the container which will hold the urine sample. You will receive instructions on how and when to collect the urine. This could be a single sample or several samples taken over time.

There are a few things to remember before the test. First, avoid working out right before the test. If you have a vaginal discharge or are on your period, let your doctor know. You can resume your usual activities right away after the test.

How Is It Done?

You need to provide a urine sample. The doctor will decide whether the sample can be taken randomly or if it must be taken over a specific period (such as over 4 hours, overnight, or 24 hours). In either situation, you will be provided a container and instructions for collecting a urine sample correctly. The sample will then be tested to determine how much albumin or protein is present.

Your physician may prescribe a blood test to look for additional signs of kidney disease (to check for the presence of wastes that the kidneys should ordinarily filter out of the blood if they are working properly).

Let us look at the different ways the test can be done.

Random one-time test

The best urine sample to determine albumin levels is the one taken in the morning. Here is how to properly collect the sample:

• Before you collect the urine, wash your hands
• Get the container ready
• If the container has a lid, remove it and place it down with the inner surface facing up
• Clean the genitals
• Start urinating in the urinal or toilet
• After a few seconds of the urine flowing, put the container into the stream. Collect around 60 mL (2 fl oz) of this "midstream" urine without stopping the flow. Again, avoid touching your genitals with the container's rim
• Finish urinating
• Replace the container's lid[
• Wash your hands properly once you are done

Specific period of time test

In this type of urine albumin test, you collect your urine for a set time, for instance, over 4 or 24 hours. Your physician will hand you a large container that can hold around 4 L. (1 gal) of fluid. The container will be used to collect the urine.

After you get out of bed, empty your bladder in the morning. But you do not need to collect this urine. First, however, note the time you began.

Collect all of your urine for the designated amount of time. During this period, save your urine in a tiny, clean container whenever you urinate. After that, add the urine to the big container. Avoid putting your fingers into either container.

The urine sample should be free of stool (feces), menstrual blood, pubic hair, toilet paper, or anything else. For the duration of collection, store the collected urine in the refrigerator.

At or shortly before the end of the collection period, empty your bladder for the final time. Fill the big container with this urine. After that, note the time. Submit the entire sample to the lab after the required time is completed.

A urine dipstick test

This has a test strip that changes color depending on how much albumin is present in the sample. A dipstick test does not exactly measure the amount of albumin. Therefore, the results are only a semi-quantitative value. Dipstick tests can be carried out in a hospital, health center, or doctor's office.

An albumin-to-creatinine ratio test

A one-time sample of urine, commonly referred to as a "spot" sample, is used in an albumin-to-creatinine ratio test to assess both albumin and creatinine. A chemical byproduct of normal muscle action called creatinine is generally excreted from the body through urine. This ratio test is an alternative method to determine your total daily urine albumin level without collecting a complete 24-hour urine sample because total daily creatinine output is generally stable.

Are There Any Risks?

There are no known risks from taking this test.

Results

Receiving Test Results

A urine dipstick test yields result quickly, typically within a few minutes. However, this test does not reveal the exact amount of albumin. The results can typically be discussed with your doctor at the same office visit.

When you submit a spot urine test, a laboratory typically measures the albumin-to-creatinine ratio, and the results are usually available in a matter of a few business days. However, even though it's uncommon, your doctor's office occasionally has a device that makes it possible to detect albumin levels without sending your sample to a lab.

Your 24-hour urine sample will be sent to the lab to determine the total albumin level. The findings should be available a few days later.

You can obtain a copy of the test results via mail or an online health portal for urine albumin tests that a lab has evaluated. In addition, your doctor may contact you by phone or email to discuss your test results.

Interpreting The Results

Different test results can point to normal kidney function. Your healthcare practitioner will go through the ranges and your particular results with you. High levels could indicate renal damage or disease. Your doctor would probably repeat the test if the results suggest that you have a high level of protein or albumin.

Your healthcare professional may request additional tests to examine your kidney function further if the results of your second test are equally high. Treatment of either diabetes or high blood pressure, the two most common causes of albuminuria, may decrease albumin in the urine or stop it from developing into renal disease. Following the diagnosis of albuminuria or microalbuminuria, some blood pressure drugs (ACE inhibitors and angiotensin II receptor blockers) are particularly beneficial for reducing kidney damage.

Certain medical facilities or labs may use an estimated albumin excretion rate (eAER) to report the results of urine albumin tests. In this calculation, the albumin-to-creatinine ratio is considered, and the projected daily creatinine level can be changed depending on the individual's body type, age, sex, and race. Even though it is not frequently utilized, the eAER might be most helpful if your daily creatinine production is abnormal.

Can I Take The Test At Home?

You can do some urine albumin tests at home. However, albumin-to-creatinine ratio testing is not generally done at home.

 At-home test kits are often divided into two categories:

1. Self-test kits

You can use them to collect and analyze the sample at home. A special paper or test strip is dipped into a cup of urine that you have collected. These kits are dipstick tests. The color of the test strip varies depending on how much albumin is detected. A result is a semi-quantitative number, but it can indicate whether your urine has a high albumin content.

2. Self-collection kits

In this kind of test, you collect your test sample at home and send it to a lab for examination. Almost all 24-hour urine samples must be collected by yourself using specialized bags or containers that your doctor will supply.

Each method of urine albumin testing has advantages and disadvantages. Talk to your doctor about the best test for you and whether you can do it at home.

How Much Does The Test Cost?

The approximate cost of an albumin urine test will vary depending on the following factors:

• Whether you do your test using a spot urine sample, dipstick, or 24-hour urine collection
• Whether any measurements besides albumin have been taken
• The location of the test, including whether it was a point-of-care test
• Your health insurance
• Individual fees for office visits, any technical help required to collect your sample, and laboratory analysis may make up the total cost of this testing

Insurance frequently pays all or part of the cost of urine albumin testing when it is advised by a physician. However, co-payments or other out-of-pocket expenses may still increase your deductible.

Consult your physician and your health insurance provider for the most detailed information regarding the anticipated expenses of a urine albumin test.

Things To Ask Your Doctor

While speaking with your doctor about the test results, bring up some of the following queries to help you better comprehend the results of your urine albumin test:

• What type of albumin urine test did I take?
• Was my result normal or unexpected?
• What do you make of the results of my test? What do you believe to be the test result's most likely cause?
• Should I retake this test? If yes, how frequently?
• How accurate was the urine albumin test I underwent?
• Do you recommend any additional testing as a follow-up? What are the benefits and drawbacks of the various alternatives for follow-up testing?

Resources:

• Maddukuri G. Proteinuria. Merck Manual Professional Edition. Updated September 2022. https://www.msdmanuals.com/professional/genitourinary-disorders/symptoms-of-genitourinary-disorders/proteinuri
• MedlinePlus: National Library of Medicine. Microalbumin Creatinine Ratio. Updated September 12, 2022. https://medlineplus.gov/lab-tests/microalbumin-creatinine-ratio/
• Gounden V, Bhatt H, Jialal I. Renal Function Tests. [Updated 2022 Jul 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507821/
• Haider MZ, Aslam A. Proteinuria. [Updated 2022 Dec 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK564390/
• Moman RN, Gupta N, Varacallo M. Physiology, Albumin. [Updated 2022 Dec 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459198/
• National Institute of Diabetes and Digestive and Kidney Diseases. Albuminuria: Albumin in the Urine. Updated October 2016.mhttps://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/tests-diagnosis/albuminuria-albumin-urine
• National Institute of Diabetes and Digestive and Kidney Diseases. Assess Urine Albumin. https://www.niddk.nih.gov/health-information/professionals/clinical-tools-patient-management/kidney-disease/identify-manage-patients/evaluate-ckd/assess-urine-albumin
• National Institute of Diabetes and Digestive and Kidney Diseases. Urine Albumin. https://www.niddk.nih.gov/health-information/professionals/clinical-tools-patient-management/kidney-disease/laboratory-evaluation/urine-albumin

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