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Factor XIII Activity (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. Low levels may indicate bleeding disorders or other blood-related conditions.

Quick summary

["Factor XIII helps your blood clot properly and supports healing—low levels can raise concerns about bleeding risks or clotting issues."]

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

Key facts at a glance

LOINC
57760-1
Short code
Fact XIII Inhib PPP Ql
Synonyms
Fact XIII Inhib PPP Ql
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
coag
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 order this test if you have symptoms like excessive bleeding (e.g., bruising, nosebleeds, or heavy menstrual periods), prolonged wound healing, or if you’re undergoing surgery or a procedure that increases bleeding risk. It may also be checked in people with inherited bleeding disorders or those taking blood thinners.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if your blood is drawn from a vein. If you’re taking blood thinners, let your provider know before scheduling.

How the Test Works

A small sample of your plasma is taken from a vein in your arm. The sample is analyzed to measure Factor XIII activity using a specialized lab method that detects its ability to help blood clot.

What the Results Mean

Results are typically reported as a percentage or ratio compared to a standard. A lower than expected result may suggest a deficiency in Factor XIII, which could affect clotting or wound healing. Your provider will discuss the meaning of your specific result with you.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Factor XIII Activity

Frequently asked questions

What are the normal reference ranges for this test?
Normal reference ranges can vary by lab and method. A low result may indicate a bleeding disorder like Factor XIII deficiency, which can cause excessive bleeding during surgery, trauma, or childbirth. High results are less commonly significant but may be checked in rare cases of clotting disorders.
Can I eat or drink before this test?
Most labs recommend fasting for 8–12 hours before plasma Factor XIII testing if directed by your provider. If you’re unsure, ask your healthcare team or lab technician for guidance.
Will this test affect my medications?
If you’re on blood thinners (e.g., warfarin, heparin), inform your provider before testing. They may adjust your dose or monitor you closely. Factor XIII testing itself does not typically interact with other medications.
  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