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Alpha-1 Antitrypsin (Serum) Level

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of Alpha-1 Antitrypsin in your blood serum, a protein that helps protect your lungs and liver from damage caused by enzymes released during inflammation.

Quick summary

["A1AT levels help assess risk for lung diseases like emphysema and liver conditions like cirrhosis."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
38027-9
Short code
Deprecated US Kdny-Bl Bx needle guide
Synonyms
Deprecated US Kdny-Bl Bx needle guide
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
us
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have a family history of lung diseases, liver problems, or if symptoms like chronic cough, shortness of breath, or unexplained fatigue appear. It’s also used in monitoring conditions like chronic obstructive pulmonary disease (COPD) or cirrhosis.

What to Expect Before the Test

No special preparation is needed. You’ll typically have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

Lower-than-normal levels may indicate genetic disorders (like Alpha-1 Deficiency) or liver disease. Higher-than-normal levels may be seen in conditions like chronic inflammation or certain infections. Your provider will discuss results in the context of your health history.

Common Conditions Linked to A1AT Levels

Low A1AT is strongly linked to Alpha-1 Deficiency, which can cause lung diseases (e.g., emphysema) and liver disease (e.g., cirrhosis). High levels may be associated with chronic inflammatory conditions or liver disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-1 Antitrypsin (A1AT)

Frequently asked questions

What causes low Alpha-1 Antitrypsin levels?
Low A1AT levels are often due to a genetic mutation (Alpha-1 Deficiency). Other rare causes may include certain liver diseases or chronic inflammatory conditions. If you have a family history, genetic testing may be recommended.
How is Alpha-1 Antitrypsin tested?
The test involves drawing blood from a vein in your arm. The sample is sent to a lab for analysis using an immunoassay method to measure the protein concentration.
Can lifestyle changes affect A1AT levels?
While lifestyle factors like smoking or heavy alcohol use can worsen lung or liver diseases linked to A1AT, they do not directly alter the protein’s blood level. However, managing these risks may help prevent complications.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy