This test measures the amount of prealbumin in the blood. Prealbumin is a protein that is made in the liver and released in the blood. It helps carry certain hormones that regulate the way the body uses energy and other substances through the blood.
When prealbumin levels are lower than normal, it may be a sign of a poor diet (malnutrition). Your doctor may use the results of this test to make changes in your diet. He or she also may use the results to see how well supplements or protein replacement fluids are working.
Other health problems also may cause your levels to drop. You may need another blood test to be sure that a poor diet is the reason for your low prealbumin levels.
Why It Is Done
A prealbumin blood test is done to:
Check for signs of a poor diet (malnutrition).
Find out if you're getting enough nutrients, mainly protein, in your diet. Protein is important for tissue growth and tissue healing.
Keep track of your nutrition while you're in the hospital or before and after surgery. Poor nutrition can slow healing and recovery.
See how well supplements or protein replacement fluids are working.
How To Prepare
Before your prealbumin test, tell your doctor if you:
Are taking any prescription or over-the-counter medicines.
Are or might be pregnant.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
The health professional taking a sample of your blood will:
Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
Clean the needle site with alcohol.
Put the needle into the vein. More than one needle stick may be needed.
Attach a tube to the needle to fill it with blood.
Remove the band from your arm when enough blood is collected.
Put a gauze pad or cotton ball over the needle site as the needle is removed.
Put pressure on the site and then put on a bandage.
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having a blood sample taken from a vein.
You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
Ongoing bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.
This test measures the amount of prealbumin in the blood.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
You may not be able to have the test or the results may not be helpful if:
You're taking certain medicines, such as estrogens, androgens, birth control pills, amiodarone (a heart rhythm-control medicine), anabolic steroids, or prednisolone (a type of steroid medicine).
You have a long-term (chronic) health problem, especially if the condition interferes with what you're able to eat or drink.
What To Think About
The prealbumin blood test is often better than an albumin protein test to check for signs of malnutrition. An albumin test can show changes in your protein levels over the past few weeks. But a prealbumin test shows these changes over an even shorter period of time (a couple of days). The sooner your doctor can see changes in your protein levels, the sooner he or she will know if you need to make any changes in your diet or if supplements or protein replacement fluids are working.
Your doctor may order a total serum protein test to be sure that a poor diet is the reason for your low prealbumin levels.
Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
How this information was developed to help you make better health decisions.