Summary

• Albumin is a protein that is found in the plasma part of your blood.
• It is the most common blood protein, and its main roles are to stop fluid from leaking out of your blood vessels into surrounding tissues and to transport substances including vitamins, hormones and waste products around your body.
• Since albumin becomes low in many different diseases and disorders, measuring albumin is done when investigating a wide range of health conditions, especially liver disease, kidney disease, nutritional status and inflammatory conditions.
• Albumin is included in Liver Function Tests (LFTs) a standard group of tests that is routinely used to check the health of the liver.

What is albumin?

Blood plasma is the liquid part of the blood. A pale-yellow fluid, it represents about half of the content of whole blood, and it contains water, salts and proteins. Many proteins float in the plasma and albumin is by far the most common of these. It represents more than half of the plasma's total protein content. Albumin is made in the liver.

Albumin’s important roles

Keeping fluid in balance

Albumin keeps the fluid part of your blood from leaking out of your blood vessels and into other tissues. Proteins in the blood, like albumin, are molecules that are too large to pass through the blood vessel walls and the pressure this creates draws water back into the blood vessels (osmosis). The pulling force of these proteins also prevents water from leaking out into surrounding tissues. This stops fluid building up in your lungs and other parts of your body.

Transporting hormones, enzymes, nutrients and waste products around your body

Albumin moves many small molecules through the blood. It binds to and transports a wide range of substances, including:

• waste products
• vitamins and minerals
• hormones
• enzymes
• chemicals, drugs and medications.

Why get tested?

Since albumin levels are affected by many different disorders, albumin testing is used to help diagnose and manage a range of conditions.

People who have chronic liver disease and kidney disorders are at highest risk of developing low albumin levels.

Liver disease

Low albumin levels can be caused by conditions that affect the liver's normal ability to make albumin. It is typically measured as part of Liver Function Tests (LFTs). This is a standard group of tests that is routinely used to check the health of the liver.

Performed on the same blood sample, LFTs measure several substances made by the liver. Looked at together, along with your symptoms and medical history, they help build a picture of your liver’s health. Either higher or lower than normal levels of these substances can indicate a problem with your liver.

Liver Function Tests include tests for albumin, the enzymes gamma-glutamyl transferase (GGT), alanine transaminase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST) and bilirubin, a breakdown product from red blood cells that is removed from the body by the liver.

The LFT can help differentiate what type of liver disease you have. Albumin stays in the blood for about 20 days, so recent, short-term health issues that affect albumin levels may not be detected. Low albumin levels are more often associated with chronic ongoing conditions. For more information see LFTs.

Kidney disease

Your kidneys filter your blood and removes waste and excess fluid from your body, which are disposed of in urine. Normally, when they are working properly, only a tiny amount of albumin leaks into your urine. Damaged kidneys let albumin pass into the urine and the more your kidneys are damaged the more albumin will be found in your urine. This is called albuminuria. As more albumin leaks into the kidneys, less albumin is kept in the blood, and this is why blood albumin levels drop in kidney disease. If this is suspected, you may also be asked to have a microalbumin (albumin-creatinine ratio) urine test. The test can be done on a single sample, or on a series of urine samples collected over 24 hours, called a 24-hour urine test.

Inflammation, injury and infection

Inflammation in the body causes albumin levels to fall. Inflammation is part of your immune system’s response to injury and infection. The immune system releases substances that make your blood vessel walls more permeable – leakier - allowing more fluid to escape into the surrounding tissues. This causes the swelling that comes with inflammation. As part of this, it is easier for albumin to move from the blood into the surrounding tissues, leading to a drop in albumin in the blood.

Malnutrition and inflammatory intestinal disorders

Amino acids are the building blocks of proteins including albumin. If you are not getting enough amino acids through your diet your liver may not be able to make enough albumin. Low albumin levels can be a sign that your body isn't getting enough amino acids in your diet or enough calories to properly process protein. This may be due to conditions that cause malabsorption or malnutrition. Malabsorption is a general term for a wide range of disorders that affect your ability to absorb nutrients from your food.

If you have an inflammatory disorder of the intestines such as coeliac disease, Crohn's disease, or Ulcerative Colitis (UC) you may develop lower albumin levels. Here, the problem is twofold - these conditions prevent your intestines from properly absorbing nutrients like amino acids and at the same time inflammation in the body causes albumin levels to fall.

Dehydration: Severe or chronic dehydration is a common cause of high albumin levels. High albumin levels usually reflect dehydration although the test is not used for this purpose.

Pregnancy: Albumin is low during pregnancy due to the increase in blood volume.

The difference between albumin, microalbumin, and prealbumin.

Albumin (in blood) and microalbumin (in urine) are the same molecule, however prealbumin, despite the similar-sounding name, is a completely unrelated molecule. It is not a precursor of albumin. It is primarily responsible for moving certain hormones and vitamins around the body.

Although prealbumin was once used to monitor nutritional status, it has been demonstrated that prealbumin levels are affected by inflammation and injury. Albumin is now considered a better test to assess nutrition and is a more widely available test than prealbumin.

The microalbumin test, more correctly termed the albumin/creatinine ratio test, measures very small levels of albumin in your urine and may indicate whether you are at risk for developing kidney disease.

Having the test

Sample

Blood.

Any preparation?

None.

Your results

Reading your test report

Your results will be presented along with those of your other tests on the same form. You will see separate columns or lines for each of these tests.

Albumin tests alone do not diagnose health conditions, but they can provide important information to help pinpoint the problem. Once a diagnosis has been confirmed, albumin tests are often used to monitor your condition and to make sure that any treatment you are having is working.

Reference intervals

Your results will be compared to reference intervals (sometimes called a normal range).

• Reference intervals are the range of results expected in healthy people.
• When compared against them your results may be flagged high or low if they sit outside this range.
• Many reference intervals vary between laboratories so only those that are standardised or harmonised across most laboratories are given on this website.

If your results are flagged as high or low this does not necessarily mean that anything is wrong. It depends on your personal situation. Your results need to be interpreted by your doctor.

Any more to know?

Albumin is sometimes used as a treatment to:

• help restore blood albumin levels
• help manage liver disease and prevent ascites (where fluid builds up in your abdominal cavity) (especially in the later stages)
• prevent kidney failure
• increase blood volume and reduce problems in blood circulation (such as when someone is suffering shock)
• help manage infections, including sepsis
• help manage severe skin burns

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think may help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

More information

Pathology and diagnostic imaging reports can be added to your My Health Record. You and your healthcare provider can now access your results whenever and wherever needed.

Get further trustworthy health information and advice from healthdirect.