---
title: "What does a low Fibrinogen mean?"
type: biomarker-interpretation
url: "https://www.test-well.com/biomarkers/fibrinogen/low"
biomarker: Fibrinogen
direction: low
reference_range:
  - "age 18+: 200 – 400 mg/dL"
reviewed_at: 2026-09-08
review_status: reviewed
date_published: 2026-09-05
---

# What does a low Fibrinogen mean?

> Low fibrinogen means either the liver is making less (advanced liver disease, malnutrition) or it is being consumed faster than it can be made — disseminated intravascular coagulation in sepsis or severe illness, major bleeding, or after thrombolytic drugs. Rare inherited deficiencies exist. A low fibrinogen raises bleeding risk and, below about 100 mg/dL, is a finding to act on the same day.


## When does this result need same-day care?

- Fibrinogen under ~100 mg/dL, or any low value with active bleeding — emergency care

## What is the normal range for Fibrinogen?

- age 18+: 200 – 400 mg/dL

Can reflect liver disease, severe bleeding, or rare genetic factor deficiency.

## What are the common causes of low Fibrinogen?

1. Advanced liver disease, cirrhosis
2. Disseminated intravascular coagulation (sepsis, trauma, obstetric emergencies, some leukemias)
3. Massive bleeding or transfusion, thrombolytic therapy
4. Malnutrition, L-asparaginase chemotherapy
5. Inherited afibrinogenemia or dysfibrinogenemia (rare)

## What symptoms go with low Fibrinogen?

- Easy bruising, prolonged bleeding, nosebleeds
- Often none when mildly low

## What do clinicians usually check next?

- PT/INR, aPTT, platelet count, D-dimer, liver panel
- Hematology review for persistent unexplained low values

Follow-up tests at TestWell: [PT and PTT (Prothrombin & Partial Thromboplastin Time)](https://www.test-well.com/tests/pt-and-ptt) ($54.99), [D-Dimer](https://www.test-well.com/tests/d-dimer) ($69.99).

## How do you recheck Fibrinogen?

| Test or panel | Type | Price | Fasting | Results |
| --- | --- | --- | --- | --- |
| [Blood Clotting Panel](https://www.test-well.com/tests/blood-clotting-panel) | Panel (4 tests) | $149.99 | No | 3–7 business days |
| [Inflammation Panel](https://www.test-well.com/tests/inflammation-panel) | Panel (7 tests) | $119.99 | Yes | 2–5 business days |
| [Total Body Panel](https://www.test-well.com/tests/total-body-panel) | Panel (49 tests) | $499.99 | Yes | 5–10 business days |
| [Fibrinogen Activity](https://www.test-well.com/tests/fibrinogen-test) | Test | $22.99 | No | 2–4 business days |

Plus one $6 lab processing fee per order; physician authorization included.

## Common questions

### Can fibrinogen be low in a healthy person?

Mild lows occasionally appear in slim, very fit people and some inherited variants without symptoms. Anything under 150 mg/dL, or a drop from a previous result, should be repeated and explained.

## Related

- [What does a high Fibrinogen mean?](https://www.test-well.com/biomarkers/fibrinogen/high)
- [Fibrinogen reference ranges](https://www.test-well.com/biomarkers/fibrinogen)
- [Glucose reference range](https://www.test-well.com/biomarkers/glucose)
- [Creatinine reference range](https://www.test-well.com/biomarkers/creatinine)
- [eGFR reference range](https://www.test-well.com/biomarkers/egfr)

## Sources

- [AACC Lab Tests Online](https://www.testing.com/tests/fibrinogen/)
- [MedlinePlus (NIH) — Fibrinogen blood test](https://medlineplus.gov/ency/article/003650.htm)

---

Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-08. Review policy: https://www.test-well.com/editorial-policy

Canonical page: https://www.test-well.com/biomarkers/fibrinogen/low
Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt

Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.