Skip to content

D-dimer (serum/plasma) concentration, measured by mass concentration via immunoassay

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 for blood clots or clot-related conditions.

Quick summary

["D-dimer helps diagnose or monitor blood clotting disorders, including deep vein thrombosis (DVT) or pulmonary embolism."]

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

Key facts at a glance

LOINC
63231-5
Short code
dsDNA IgG Plr IA-aCnc
Synonyms
dsDNA IgG Plr IA-aCnc
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

What Is D-Dimer Used For?

D-dimer is primarily used to evaluate conditions where blood clots may form or dissolve. It can help rule out certain types of blood clots or guide decisions about further testing or treatment, such as blood thinners.

How Is the Test Performed?

A small blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure D-dimer levels. Results are typically available within 24 hours.

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 a history of blood clots. It’s also used in certain situations to help determine if you need further imaging or treatment for suspected clotting disorders.

What Do the Results Mean?

High levels of D-dimer suggest recent clot formation and may indicate conditions like DVT or pulmonary embolism. Very low levels are usually normal. Your doctor will interpret results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

D-dimer is a key marker for diagnosing venous thromboembolism (VTE), such as deep vein thrombosis or pulmonary embolism. While a positive result strongly suggests clotting activity, it’s not definitive on its own. Doctors often use it alongside other tests or imaging to confirm or rule out these conditions. It can also help guide decisions about anticoagulant therapy.

Short name

D-dimer

Frequently asked questions

Why might my D-dimer test be ordered?
Your doctor may order a D-dimer test if you have symptoms like unexplained leg swelling, chest pain, or shortness of breath, or if you’ve had a recent injury or surgery that increases your risk of blood clots. It’s also used in certain situations to help decide if further tests, like imaging, are needed.
What does a high D-dimer level mean?
A high D-dimer level often means you’ve recently had a clot break down, which could indicate conditions like deep vein thrombosis (DVT) or pulmonary embolism. However, other conditions, such as inflammation or certain cancers, can also cause elevated levels. Your doctor will discuss the results with you and may recommend additional testing.
Can D-dimer levels change over time?
Yes, D-dimer levels can change depending on whether you’re forming or breaking down clots. If you’re on blood thinners, your levels may drop over time as the medication works. If you’ve had a clot, your levels may remain elevated until the body clears the fragments. Always follow up with your healthcare provider for personalized guidance.
  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