Fibrinogen Activity
Other names: FIBRINOGEN ACTIVITY, CLAUSS
A fibrinogen activity test is also known as a Factor I assay. It’s used to determine the level of fibrinogen in your blood. Fibrinogen, or factor I, is a blood plasma protein that’s made in the liver. Fibrinogen is one of 13 coagulation factors responsible for normal blood clotting.
When you start to bleed, your body initiates a process called the coagulation cascade, or clotting cascade. This process causes coagulation factors to combine and produce a clot that will stop the bleeding. If you don’t have enough fibrinogen or if the cascade isn’t working normally, clots will have difficulty forming. This can cause excessive bleeding.
Fibrinogen is measured in milligrams per deciliter (mg/dL):
- A normal value for fibrinogen is between 200 and 400 mg/dL.
- A fibrinogen value of less than 50 mg/dL may mean you're in danger of bleeding after surgery.
- A fibrinogen value of more than 700 mg/dl may mean you're in danger of forming clots that could harm your heart or brain.
Lab Results Explained and Tracked
What does it mean if your Fibrinogen Activity result is too high?
High fibrinogen values may also be associated with:
-
Infections and inflammation
-
Cancer
-
Rheumatoid arthritis
-
Nephrotic syndrome
-
Heart attack
-
Stroke
-
Pregnancy
All Your Lab Results.
One Simple Dashboard.
Import, Track, and Share Your Lab Results Easily
Import, Track, and Share Your Lab Results
Import lab results from multiple providers, track changes over time, customize your reference ranges, and get clear explanations for each result. Everything is stored securely, exportable in one organized file, and shareable with your doctor—or anyone you choose.
Cancel or upgrade anytime
What does it mean if your Fibrinogen Activity result is too low?
Low fibrinogen levels can cause thrombosis due to an increase in coagulation activity. Thrombosis refers to the formation of a blood clot inside of a blood vessel. The clot blocks the normal flow of blood through the circulatory system. This can lead to serious medical conditions such as heart attack and stroke.
The three types of fibrinogen deficiency are afibrinogenemia, hypofibrinogenemia, and dysfibrinogenemia:
Afibrinogenemia:
Afibrinogenemia is the total absence of fibrinogen. This disorder affects 5 out of every 10 million people. This disorder causes the most severe bleeding out of the three forms of fibrinogen deficiency.
Hypofibrinogenemia:
Hypofibrinogenemia is an abnormally low level of fibrinogen. In this case, the test would show a level between 0.2 and 0.8 grams per liter. This form of the deficiency is less common than afibrinogenemia and it can cause mild to severe bleeding.
Dysfibrinogenemia:
Dysfibrinogenemia is a condition in which fibrinogen levels are normal, but the protein doesn’t function properly. Dysfibrinogenemia affects only about one in every 1 million people. The condition rarely causes a bleeding problem and instead is more likely to cause thrombosis.
Article Review & Sources
All our content is backed by peer-reviewed studies, academic research, and trusted medical sources. We're committed to accuracy and transparency — see our editorial policy for details.
Laboratories
Bring All Your Lab Results Together — In One Place
We accept reports from any lab, so you can easily collect and organize all your health information in one secure spot.
Pricing Table
Gather Your Lab History — and Finally Make Sense of It
Finally, Your Lab Results Organized and Clear
Personal plans
$79/ year
Advanced Plan
Access your lab reports, explanations, and tracking tools.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 5 reports entered for you
- Cancel or upgrade anytime
$250/ once
Unlimited Account
Pay once, access everything—no monthly fees, no limits.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 10 reports entered for you
- No subscriptions. No extra fees.
$45/ month
Pro Monthly
Designed for professionals managing their clients' lab reports
- Import lab results from any provider
- Track lab results for multiple clients
- Customize reference ranges per client
- Export lab histories and reports
- Begin with first report entered by us
- Cancel or upgrade anytime
About membership
What's included in a Healthmatters membership
Import Lab Results from Any Source
See Your Health Timeline
Understand What Your Results Mean
Visualize Your Results
Data Entry Service for Your Reports
Securely Share With Anyone You Trust
Let Your Lab Results Tell the Full Story
Once your results are in one place, see the bigger picture — track trends over time, compare data side by side, export your full history, and share securely with anyone you trust.
Bring all your results together to compare, track progress, export your history, and share securely.
What Healthmatters Members Are Saying
We implement proven measures to keep your data safe.
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.