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Factor XIII Activity (Serum/Plasma)

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

This test measures the activity level of Factor XIII, a protein involved in blood clotting and wound healing.

Quick summary

["Factor XIII helps stabilize blood clots and supports tissue repair—low levels may raise concerns about bleeding risks or clotting disorders."]

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

Key facts at a glance

LOINC
50637-8
Short code
Fact XIII Inhib PPP Ql Chro
Synonyms
Fact XIII Inhib PPP Ql Chro
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
chromo
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 doctor may recommend this test if you have a history of unusual bleeding, excessive bruising, or clotting problems. It could also be checked before surgeries, especially if you’re taking blood-thinning medications or have conditions like liver disease or blood disorders.

What to Expect Before the Test

No special preparation is needed, but avoid consuming alcohol for 24 hours before the test. Fasted or non-fasted states don’t typically affect Factor XIII activity, but your doctor may specify if you have specific instructions.

How the Test Works

A blood sample is drawn from a vein, usually in your arm. The sample is then analyzed to measure Factor XIII activity levels, often using an immunoassay or clotting-based method to detect its functional presence.

What the Results Mean

Results are typically reported as a percentage or ratio compared to a standard reference. Low levels may indicate a bleeding disorder (e.g., Factor XIII deficiency), while normal levels suggest healthy clotting function. Your doctor will interpret results in the context of your medical history and symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Factor XIII Activity

Frequently asked questions

What does a low Factor XIII level mean?
Low Factor XIII activity can increase the risk of bleeding, especially after injuries, surgeries, or childbirth. It may also be linked to conditions like liver disease, where protein production is impaired, or certain genetic disorders. Your doctor may recommend further testing or treatment to manage symptoms.
What does a high Factor XIII level mean?
Elevated Factor XIII levels are less common but may occur in certain inflammatory conditions, infections, or as a side effect of medications. High levels alone usually don’t cause symptoms unless they interfere with normal blood clotting processes, which is rare.
Can lifestyle changes affect Factor XIII levels?
No known lifestyle factors (like diet or exercise) significantly alter Factor XIII activity. However, conditions like liver disease or chronic inflammation may impact production, so managing those conditions can indirectly support stable levels.
  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