Doctor's Assessment Included
Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
Thrombin Time
Thrombin Time completes a comprehensive coagulation assessment by evaluating the final clotting step — fibrinogen to fibrin conversion.
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.