Why Does Prealbumin Change Quickly?
Prealbumin, also called transthyretin, is a protein mainly made by the liver. It carries thyroid hormones and vitamin A-related proteins through the bloodstream.
Prealbumin remains in the blood for a relatively short time. Its level may therefore change more quickly than some other blood proteins when a person becomes seriously ill or their nutritional intake changes.
A Prealbumin Blood Test measures the amount of this protein in the blood. Healthcare providers use this to keep track of people’s nutritional assessment, especially of those who are sick or in the hospital.
Is Prealbumin a Nutrition Test?
Prealbumin has traditionally been used to assess nutrition because low levels may suggest that the body is not receiving or absorbing enough nutrients.
However, a low result does not always mean that a person is malnourished. Inflammation, infection, injury and serious illness can also reduce prealbumin levels, even when the person is receiving adequate nutrition.
For this reason, the result should be considered alongside the person’s diet, weight changes, medical condition and other laboratory findings. Some medical professionals no longer recommend using prealbumin alone to diagnose malnutrition.
When Might a Prealbumin Test Be Needed?
A healthcare provider may request this test when assessing possible malnutrition, monitoring nutritional support, or following recovery after surgery, burns, or serious illness.
It may also be considered for people with
- Unexplained weight or muscle loss
- Reduced appetite
- Wounds that are healing slowly
- Getting sick very often
- Long-term tube feeding
- Conditions that increase nutritional needs.
The result may be compared over time with weight changes, food intake, and inflammatory markers. Symptoms alone cannot confirm low prealbumin, so a wider nutritional and medical assessment is still needed.
Before the Blood Sample Is Taken
Fasting is not usually required unless other blood tests have been ordered at the same time.
Tell your healthcare provider about any medicines, supplements, tube feeding, or intravenous nutritional support you receive. Certain medicines may affect the result, but you should not stop using prescribed medication unless instructed to do so.
Continue drinking water normally unless you have received different instructions.
How Is the Blood Collected?
A healthcare professional cleans the skin, usually on the inside of the elbow, and inserts a small sterile needle into a vein.
A small amount of blood is collected into a tube. The needle is then removed, and pressure is applied to the area.
The process usually takes only a few minutes. You may experience mild bruising afterwards.
How Is Prealbumin Measured?
The laboratory separates the serum from the blood cells and measures the concentration of prealbumin.
The result may be reviewed with tests such as:
- C-Reactive Protein
- Albumin
- Total protein
- Kidney & liver function tests
- Complete Blood Count
- Weight and dietary assessments
Looking at several findings together helps the healthcare provider decide whether the result is more likely related to nutrition, inflammation, liver function, or another condition.
Why Is C-Reactive Protein Often Checked Too?
C-Reactive Protein, or CRP, rises when inflammation is present, while prealbumin may fall during the same inflammatory response.
For example, low prealbumin with a high CRP result may be more strongly influenced by infection, injury, or inflammation than by food intake alone.
Reviewing these two markers together can provide more context, although neither result can diagnose malnutrition by itself.
What Is the Expected Prealbumin Level?
A commonly used adult reference range is approximately:
- 16–30 mg/dL
Some laboratories may report the result in milligrams per litre rather than milligrams per decilitre.
The expected range can differ based on the laboratory, testing method, age and clinical setting. Always use the reference interval printed on your own report.
The reference ranges vary depending on the laboratory and the methodology used. Individuals must consult their healthcare provider for correct interpretation of the results.
What Can a Low Prealbumin Level Mean?
A low result means less prealbumin than expected was measured in the blood.
Possible reasons include:
- Inadequate nutritional intake
- Inflammation
- Chronic or severe illness
- Liver disease
- Some digestive conditions
- Increased thyroid activity
A low result cannot show which condition is responsible. In an individual who is ill, injured, or recovering from surgery, Prealbumin may be affected both by inflammation and poor nutrition.
What Can a High Prealbumin Level Mean?
High prealbumin levels are less common and are not usually used to diagnose a specific condition.
They may sometimes occur with:
- Reduced kidney function
- High-dose corticosteroid treatment
- Certain medical conditions
- Changes caused by medicines
A high result does not confirm any of these conditions and must be considered with other test results and the person’s medical history.
Why One Result Is Not Enough
A single prealbumin result only shows the level at the time the blood was taken.
The healthcare provider may look at whether the level:
- Increases after nutritional support
- Falls during infection or inflammation
- Changes during recovery
- Remains low despite treatment
- Matches changes in weight, appetite and strength
Repeated results may be more useful than one measurement, but improvement in prealbumin does not necessarily prove that malnutrition has been corrected.
What May Be Checked Next?
If the result is outside the laboratory range, the healthcare provider may recommend:
- A detailed dietary and weight assessment
- C-Reactive Protein or other inflammation tests
- Albumin and total protein tests
- Kidney & liver function tests
- Thyroid tests
- Complete Blood Count
- Vitamin and mineral tests
- Tests for poor nutrient absorption
The next step depends on the person’s symptoms, illness, diet and other laboratory results.
Treatment is aimed at the underlying cause rather than the prealbumin number itself. This may involve nutritional support, treatment of infection or inflammation, or management of liver, kidney or digestive conditions.
Book An Appointment
Need a Prealbumin Blood Test? Book an appointment with Genex Clinical Laboratories for blood collection and assessment of prealbumin levels.
