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D-dimer (serum/plasma) concentration

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of D-dimer, a protein fragment produced when blood clots break down. It helps assess whether you’re at risk of blood clots or clot-related complications.

Quick summary

["D-dimer helps doctors evaluate blood clot risks and guide treatment decisions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
63228-1
Short code
dsDNA IgG CSF Ql IA
Synonyms
dsDNA IgG CSF Ql IA
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What Is D-Dimer Used For?

D-dimer is primarily used to diagnose or rule out conditions involving abnormal blood clotting, such as deep vein thrombosis (DVT) or pulmonary embolism. It can also help assess the risk of bleeding in certain medical situations.

How Is the Test Performed?

A small blood sample is drawn from a vein, usually in your arm. The blood is then processed to measure D-dimer levels. Results are typically available within 24 hours.

What Does a High or Low D-Dimer Level Mean?

High levels of D-dimer often suggest recent clot formation, which may indicate conditions like DVT or pulmonary embolism. However, D-dimer can also rise in other situations, such as inflammation or pregnancy. Low levels usually mean no significant clotting activity is detected.

When Might You Need This Test?

Your doctor 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 your risk of blood clots.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

D-Dimer

Frequently asked questions

Why is D-dimer important in diagnosing blood clots?
D-dimer is a key marker because it specifically reflects the breakdown of clots. While it’s not definitive on its own, it helps narrow down whether a patient likely has a clot-related condition or another cause for symptoms.
Can D-dimer levels change over time?
Yes, D-dimer levels can fluctuate depending on whether clotting activity is present. For example, they may decrease after successful treatment of a clot or if the body clears the fragments more efficiently.
Does diet or exercise affect D-dimer levels?
Generally, diet and exercise do not significantly alter D-dimer levels. However, certain medications (like blood thinners) or medical conditions (such as infections or cancer) can influence results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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