Serum or plasma concentration of **D-dimer** (mass concentration)
This test measures the presence of D-dimer, a breakdown product formed when blood clots dissolve. It helps assess whether abnormal clotting or clot-dissolving processes may be occurring in your body.
["D-dimer helps diagnose or monitor blood clotting disorders."]
Key facts at a glance
- LOINC
- 9931-7
- Short code
- Q wave Dpth L-V1
- Synonyms
- Q wave Dpth L-V1
- Category
- coagulation
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ekg
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is D-Dimer Used For?
D-dimer is primarily used to evaluate conditions involving blood clots or clot breakdown. It can assist in diagnosing deep vein thrombosis (blood clots in veins), pulmonary embolism (clots in the lungs), or other clotting disorders. It may also be used in certain types of cancer or after surgery to monitor clot risk.
How Is the Test Performed?
A small blood sample is drawn from your arm, typically in the morning after fasting. The blood is processed to separate serum or plasma, where D-dimer levels are measured using an immunoassay method. Results are reported in arbitrary units concentration (e.g., ng/mL).
What Are Common Reasons for Testing?
Your healthcare provider may order a D-dimer test if you have symptoms like leg swelling, chest pain, shortness of breath, or if you’ve been diagnosed with a condition that increases clot risk, such as cancer, heart disease, or recent surgery.
What Do Results Mean?
High D-dimer levels suggest recent clot formation or breakdown, which may indicate conditions like deep vein thrombosis or pulmonary embolism. Very low levels are normal. Your doctor will interpret results in the context of your symptoms and medical history.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: D-Dimer plays a key role in identifying or ruling out blood clots. While a positive test strongly suggests clotting activity, it’s not definitive on its own. Doctors may use it alongside other tests (like imaging) to guide treatment decisions, such as anticoagulant therapy for clots.
Short name
D-Dimer
Frequently asked questions
Why might my doctor recommend this test?
What if my D-dimer level is high?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy