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Fibrinogen (deprecated test, likely related to fibrinogen/fibrin degradation products or fibrinogen activity measurement)

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

This test was previously used to measure fibrinogen, a protein involved in blood clotting. Due to its obsolescence, it is no longer routinely ordered.

Quick summary

["Fibrinogen was historically checked for bleeding or clotting disorders but is now rarely requested."]

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

Key facts at a glance

LOINC
42173-5
Short code
Deprecated Tib+Fib-R XR port
Synonyms
Deprecated Tib+Fib-R XR port
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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

What This Test Was Originally Meant To Do

Fibrinogen was once measured to assess blood clotting function. It helps identify conditions like bleeding disorders (e.g., hemophilia) or clotting disorders (e.g., deep vein thrombosis). The protein helps blood form clots by converting into fibrin during injury.

Why This Test Is No Longer Used

Modern medicine relies on more specific tests like prothrombin time (PT) or activated partial thromboplastin time (aPTT) to evaluate clotting. Fibrinogen levels alone are less informative without additional context.

What Happens If This Test Is Ordered?

If your healthcare provider orders this test, it may be for research, historical records, or a specialized clinical scenario. Results are rarely actionable and are typically reviewed in the context of other tests.

Clinical Significance

While fibrinogen was once critical for diagnosing bleeding or clotting issues, its role is now secondary. Abnormal levels may still be checked in rare cases, but they are often paired with other tests for better accuracy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Why was this test marked as deprecated?
This test was deprecated because newer, more precise methods (like PT/aPTT) better evaluate blood clotting. Fibrinogen alone lacks specificity for most clinical scenarios.
Could this test still be used for anything?
Possibly in niche research or legacy cases, but it’s unlikely to be ordered for routine care. Always confirm with your provider.
What should I expect if my doctor orders this test?
You may receive a blood draw for a generic clotting-related test. Results will likely be reviewed alongside other lab findings, not standalone. Follow-up will depend on your clinical needs.
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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