D-dimer is a fragment released when a blood clot breaks down.
- Normal range (adults)
- Below 0.5 mg/L FEU (below 500 ng/mL FEU)
- Sample
- Blood
- Fasting
- Not usually needed
- Also called
- D Dimer, DDimer, Fibrin Degradation Product, FDP D-Dimer
D-Dimer normal range
| Group | mg/L FEUConventional units: US, South Asia | ng/mL FEUSI units: UK, Europe, Australia, international |
|---|---|---|
| Adults | Below 0.5 | Below 500 |
Many hospitals use a higher, age-adjusted cut-off for people over 50.
Your report may use either unit system; labs in the Gulf often print both. Ranges also vary slightly between laboratories, so the range printed on your own report is the one to go by.
Why is the D-Dimer test done?
It is used to rule out deep vein thrombosis (DVT) and pulmonary embolism. A normal result makes a clot unlikely.
What does a high D-Dimer level mean?
A raised D-dimer means clotting activity somewhere in the body, but it is not specific. It is often raised after surgery, in pregnancy, with infection and in older people.
Common causes
- Deep vein thrombosis or pulmonary embolism
- Recent surgery or injury
- Pregnancy
- Infection, including COVID-19
- Cancer
- Older age
Diet and lifestyle tips
- Stay hydrated and active
- On long journeys, walk and stretch regularly
When should you see a doctor?
Seek urgent care for a swollen painful leg, sudden breathlessness or chest pain.
Last updated
This page is for general education and is not a diagnosis. Normal ranges differ between laboratories, so always compare your result with the reference range printed on your own report, and discuss abnormal results with your doctor.