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Factor X Activity (Plasma)

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

This test measures the activity level of Factor X, a protein involved in blood clotting. It helps assess how well your blood can clot under certain conditions.

Quick summary

["Factor X activity helps identify bleeding disorders or clotting issues."]

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

Key facts at a glance

LOINC
3187-2
Short code
Fact IX Act/Nor PPP
Synonyms
Fact IX Act/Nor PPP
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 Is This Test Done?

Your healthcare provider may order this test if you have symptoms of bleeding disorders, such as excessive bruising, prolonged bleeding from cuts, or unexplained nosebleeds. It may also be used to monitor treatment for conditions like hemophilia or other clotting disorders.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into a vein in your arm to draw blood. If you’re on blood-thinning medication, let your provider know before the test.

What the Test Results Mean

Results are compared to a standard range to determine if your Factor X activity is within normal limits or if it’s too low or too high. Low levels may indicate bleeding disorders, while high levels could be due to certain medications or conditions.

Common Conditions Monitored

This test is often used to diagnose or monitor bleeding disorders like hemophilia, von Willebrand disease, or other inherited or acquired clotting problems.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Factor X Activity

Frequently asked questions

What causes Factor X activity to be low?
Low Factor X activity can be caused by inherited clotting factor deficiencies (e.g., hemophilia), liver disease (since the liver produces clotting factors), certain medications (like warfarin), or severe vitamin K deficiency.
How is Factor X activity tested?
The test measures how long it takes for plasma to clot after adding a specific activator. This is typically done using a specialized blood-clotting assay in a lab setting.
Can lifestyle changes affect Factor X activity?
While diet and lifestyle factors like smoking or alcohol use may indirectly affect liver function (which produces clotting factors), they do not directly alter Factor X activity. Always follow your provider’s advice regarding medications or supplements.
  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