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Coagulation

Thrombin Time

Thrombin Time completes a comprehensive coagulation assessment by evaluating the final clotting step — fibrinogen to fibrin conversion.

Doctor's Assessment Included

Reference Ranges

No established reference range

There is no generally applicable reference interval for thrombin time. The result depends on the reagent the laboratory uses, and Dutch laboratories therefore publish values that barely overlap: UMC Utrecht uses 10.6-16.6 seconds, LUMC 15.3-18.7 seconds and Franciscus Gasthuis 15-22 seconds. A thrombin time of 12 seconds would be normal at one laboratory and low at another. We therefore state no number: read your result against the reference interval of the laboratory that performed the test.

Unit: s

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

What It Measures

This test measures the time for plasma to clot after adding thrombin directly. It bypasses the intrinsic and extrinsic pathways, evaluating only the final fibrinogen to fibrin conversion.

Why It Matters

TT helps identify fibrinogen abnormalities (dysfibrinogenaemia), detect heparin contamination, and evaluate unexplained prolongation of PT or aPTT.

When to Test

TT is ordered when fibrinogen dysfunction is suspected, when heparin contamination needs to be ruled out, or as part of a comprehensive coagulation evaluation.

Symptoms

Low Levels

A short thrombin time is generally not clinically significant.

High Levels

A prolonged TT may indicate low or dysfunctional fibrinogen, heparin effect, high fibrin degradation products, or paraprotein interference.

Lifestyle Tips

If fibrinogen abnormalities are identified, your healthcare provider will determine the cause. Maintaining liver health through a balanced diet and moderate alcohol consumption supports normal fibrinogen production.

Frequently Asked Questions

When is thrombin time more useful than PT or aPTT?
TT specifically evaluates the final clotting step. It is particularly useful for detecting heparin contamination and diagnosing rare fibrinogen disorders.
What is dysfibrinogenaemia?
A condition where fibrinogen is present in normal amounts but does not function properly. TT can detect this.
Can medications affect thrombin time?
Yes. Heparin, direct thrombin inhibitors (dabigatran), and fibrinolytic agents can all prolong TT.

Test Products

This marker is included in the following test panels.

Thrombin Time

€16,-