D-Dimer
Haematology marker
D-Dimer
A fibrin degradation product released when a blood clot is broken down. Used to help rule out venous thromboembolism (deep vein thrombosis and pulmonary embolism) and to assess disseminated intravascular coagulation.
PED Notes
D-dimer is highly relevant to enhanced athletes because AAS increase thrombotic risk: androgen-driven erythrocytosis raises haematocrit and blood viscosity, and AAS shift haemostasis toward clotting and impaired fibrinolysis. A raised D-dimer signals active clot formation and breakdown somewhere in the body, so in a polycythaemic user with leg swelling, chest pain, or breathlessness it is an urgent finding. D-dimer is most useful for its negative predictive value: a normal result makes clinically significant clot very unlikely. It is non-specific and rises with inflammation, hard training, injury, and recent surgery. No PED lowers the healthy target, so the bodybuilder range equals the standard range.
When high
When elevated (>0.5 mg/L FEU):
- An elevated D-dimer indicates clot formation and breakdown, but it is non-specific. Causes include venous thromboembolism, recent intense exercise or muscle damage, inflammation or infection, trauma, surgery, and (rarely) disseminated intravascular coagulation.
- What to do (urgent if symptomatic): if there is calf pain or swelling, pleuritic chest pain, breathlessness, or unexplained tachycardia, seek emergency assessment; imaging (Doppler ultrasound or CT pulmonary angiogram) is needed, not more blood tests.
- If asymptomatic and recently trained hard, a mild elevation can be non-specific; repeat when rested and check haematocrit.
- For AAS users, reduce the dominant clot driver: if haematocrit is high, address it (hydration, dose reduction, therapeutic phlebotomy) and review the overall protocol with a clinician. Do not start anticoagulation without medical supervision.
History Chart
Reading History
Frequently Asked Questions
Reference Ranges
Standard Range
VitalMetrics Range