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Factor X Inhibitor Activity (Plasma)

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

This test measures the activity of Factor X inhibitor, a protein that can slow blood clotting. It may be checked if you have bleeding problems or are at risk for blood clots.

Quick summary

["Understanding your Factor X inhibitor levels helps guide treatment for bleeding disorders or clotting risks."]

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

Key facts at a glance

LOINC
3216-9
Short code
Fact X Inhib PPP-aCnc
Synonyms
Fact X Inhib PPP-aCnc
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 Is Done

Your doctor may order this test if you have symptoms like excessive bleeding (e.g., bruising, nosebleeds, or heavy menstrual periods) or if you’re taking medications that affect blood clotting. It may also be used to monitor certain inherited bleeding disorders or to check for blood clotting issues before surgery.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re on blood-thinning medications, let your doctor know before the test.

How the Test Works

The test measures how well Factor X inhibitor blocks blood clotting. A specialized lab will mix your plasma with a clotting agent and observe how long it takes for clotting to occur. The inhibitor’s presence slows this process.

What the Results Mean

Results are compared to a standard range for healthy individuals. High levels may indicate a bleeding disorder, while low levels could suggest other clotting issues or medication effects. Your doctor will interpret results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Factor X Inhibitor Level

Frequently asked questions

What does my Factor X inhibitor level tell me about my health?
High levels may point to an inherited bleeding disorder like hemophilia or acquired conditions like lupus anticoagulant. Low levels could be normal if you’re not bleeding excessively or may indicate other clotting factors are compensating. Always discuss results with your doctor.
How often should I get this test?
Your doctor may recommend follow-up tests based on your symptoms, treatment plan, or if you’re monitoring a known bleeding disorder. Regular monitoring might be needed if you’re on long-term blood-thinning therapy or have a history of clotting issues.
Can I eat or drink before this test?
You can eat and drink normally unless your doctor specifies otherwise. Avoid alcohol before the test, as it may affect blood clotting temporarily.
  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