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Fibrinogen by Nephelometry (Serum)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of fibrinogen, a protein in your blood that helps with blood clotting. It’s often checked when you have concerns about bleeding disorders or clotting issues.

Quick summary

["Fibrinogen helps control bleeding and supports blood clot formation—levels may be checked for bleeding risks or clotting problems."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
42772-4
Short code
Fibrinogen Ag PPP Neph-mCnc
Synonyms
Fibrinogen Ag PPP Neph-mCnc
Category
coagulation
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Ref low
200
Ref high
400
Critical range
60 N/A – —
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
nephelometry
CPT
85384
SNOMED
47279000
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 order this test if you have symptoms like excessive bleeding (e.g., bruising easily, nosebleeds, or heavy menstrual periods), unexplained clots, or if you’re undergoing surgery or a procedure that could affect clotting. It may also be part of a general blood panel to assess coagulation function.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the draw if your lab requires it. Wear a loose shirt for easy access. Avoid aspirin or certain blood thinners for 48 hours before testing unless directed otherwise.

What the Results Mean

Fibrinogen levels can vary based on health, age, and medications. Low levels may suggest bleeding disorders, while very high levels could indicate inflammation or liver disease. Your doctor will interpret results in relation to your overall health and symptoms.

Common Conditions Monitored

This test helps diagnose or monitor conditions like von Willebrand disease, hemophilia, disseminated intravascular coagulation (DIC), or liver disorders that affect protein production.

Reference range

Adult: 200-400 mg/dLN/A

Specimen: plasma

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Fibrinogen Level

Frequently asked questions

What causes low fibrinogen levels?
Low fibrinogen can result from liver disease (which reduces protein production), severe bleeding, certain medications (like anticoagulants), or conditions like DIC or acute infections.
What causes high fibrinogen levels?
High fibrinogen is often linked to inflammation (e.g., infections, autoimmune diseases), pregnancy, or certain cancers. It may also appear in response to stress or trauma.
Can diet affect fibrinogen levels?
Dietary factors like high-fat or inflammatory foods may indirectly influence fibrinogen indirectly (e.g., through inflammation), but this test itself doesn’t require dietary restrictions unless fasting is required for the draw.
  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 17, 2026. · Read our editorial policy