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Prealbumin Blood Test

What is a prealbumin blood test?

A prealbumin blood test measures prealbumin levels in your blood. Prealbumin is a protein that's made in your liver. Prealbumin helps carry thyroid hormones and vitamin A through your bloodstream. It also helps control how your body uses energy.

If your prealbumin levels are lower than normal, it may be a sign of malnutrition. Malnutrition is a condition where your body doesn't get enough of the nutrients that you need for good health, such as protein, vitamins, and minerals.

Malnutrition can happen if you:

Other names: thyroxine binding prealbumin, PA, transthyretin test, transthyretin, tryptophan-rich prealbumin

What is it used for?

A prealbumin test may be used to help:

  • Find out if you are getting enough nutrients, especially protein, in your diet
  • Check for nutrition problems if you have a risk of malnutrition because you:
    • Are in the hospital with certain diseases
    • Have had surgery
    • Have a serious or chronic (long-lasting) illness
    • Get dialysis treatment for kidney disease and need to avoid eating many types of food
    • Are fed by parenteral nutrition ("artificial feeding"), which means that you get a nutritional liquid through an intravenous (IV) tube

Why do I need a prealbumin blood test?

Your provider may order a prealbumin test to help diagnose and monitor problems with your nutritional health. You may also need this test before surgery or if you have symptoms of malnutrition, such as:

  • Weight loss
  • Weakness
  • Dizziness
  • Dry skin
  • Dry, brittle hair and/or hair loss
  • Feeling cold
  • Aching joints

Children with malnutrition may not grow and develop normally.

What happens during a prealbumin blood test?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a prealbumin test.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

Prealbumin levels that are lower than normal may happen with:

If you have low prealbumin levels and you are ill, injured, or recovering from surgery, it may be difficult to know exactly what is causing the low levels. Your provider may need to do other tests to find out more about your nutritional health.

Prealbumin levels that are higher than normal may happen with several conditions, including:

Prealbumin testing is not used to diagnose or monitor these conditions. If you have high prealbumin levels, your provider may order other tests to diagnose your condition.

If your prealbumin levels are not normal, it doesn't always mean you have a condition that needs treatment. Certain medicines and pregnancy can affect your prealbumin levels. If you have questions about your results, talk with your health care provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a prealbumin blood test?

Some medical experts don't think a prealbumin test is the best way to diagnose or monitor malnutrition. That's because other medical conditions can cause low prealbumin levels.

More research is needed to understand how prealbumin works in the body and what abnormal test results may mean. But many providers still find prealbumin blood tests useful for monitoring nutrition, especially in people who are seriously ill or in the hospital.


  1. Beck FK, Rosenthal TC. Prealbumin: A Marker for Nutritional Evaluation. Am Fam Physican [Internet]. 2002 Apr 15 [cited 2017 Nov 21]; 65(8):1575–1579. Available from:
  2. Eat Right [Internet]. Academy of Nutrition and Dietetics; c2022. What is Malnutrition?; [Reviewed 2021 Aug; cited 2022 May3]; [about 2 screens]. Available from:
  3. Johns Hopkins Medicine [Internet]. Johns Hopkins Medicine; c2022. Health Library: Malnutrition; [cited 2022 May 3]; [about 4 screens]. Available from:
  4. Keller U. Nutritional Laboratory Markers in Malnutrition. J Clin Med. 2019 May 31[cited 2022 May 3];8(6):775. doi: 10.3390/jcm8060775. PMID: 31159248; PMCID: PMC6616535. Available from:
  5. Mayo Clinic: Mayo Medical Laboratories [Internet]. Mayo Foundation for Medical Education and Research; 1995-2022. Prealbumin (PAB), Serum: Clinical and Interpretive; [cited 2017 Nov 21]; [about 3 screens]. Available from:
  6. Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2022. Undernutrition; [revised 2021 Jul; cited 2022 May 3]; [about 15 screens]. Available from:
  7. Merck Manual Professional Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2022. Overview of Undernutrition; [revised 2021 Jul; cited 2022 May 3]; [about 7 screens]. Available from:
  8. National Cancer Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; NCI Dictionary of Cancer Terms: malnutrition; [cited 2022 May 3]; [about 1 screens]. Available from:
  9. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests; [2022 Mar 24; cited 2022 May 3]; [about 6 screens]. Available from:
  10. Pathology Tests Explained [Internet]. Alexandria (Australia): Australasian Association for Clinical Biochemistry and Laboratory Medicine; c2022. Prealbumin; [Reviewed 2021 Mar 24; cited 2022 May 3]; [about 8 screens]. Available from:
  11. [Internet]. Seattle (WA).: OneCare Media; c2022. Prealbumin; [modified 2020 Sep 22; cited 2022 May 3]; [about 8 screens]. Available from:
  12. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2022. Health Encyclopedia: Prealbumin (Blood); [cited 2022 May 3]; [about 2 screens]. Available from:
  13. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2022. Prealbumin Blood Test; [updated 2021 Dec 27; cited 2022 May 3]; [about 6 screens]. Available from:

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.