Skip to content

D-dimer (Serum or Plasma)

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

This test measures the D-dimer protein, a breakdown product formed when blood clots dissolve. It helps assess whether you may have a blood clot in your veins or arteries.

Quick summary

["D-dimer helps diagnose or monitor blood clotting risks."]

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

Key facts at a glance

LOINC
111941-1
Short code
Dx Stom Endscpy
Synonyms
Dx Stom Endscpy
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
endoscopy
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 abnormal blood clotting, such as deep vein thrombosis (DVT) or pulmonary embolism. It can also support the evaluation of other clotting disorders or help rule out clot-related issues after certain procedures.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is then processed to measure the D-dimer levels. Results are typically available within a few hours to a day, depending on lab processing times.

What Are Possible Results?

Results are qualitative (positive or negative) rather than numerical. A positive result suggests there may be a clot-related condition, while a negative result helps confirm the absence of recent clotting activity.

When Might You Need This Test?

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 your risk of blood clots, such as prolonged immobility, recent surgery, or certain medical conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

D-dimer is a key diagnostic tool for suspected venous thromboembolism (VTE), such as DVT or pulmonary embolism. While a positive result indicates potential clotting activity, it does not definitively diagnose these conditions alone. Your doctor may use the result alongside other tests, imaging, or clinical findings to guide treatment decisions. In some cases, a negative D-dimer result can help rule out clotting disorders, reducing unnecessary further testing.

Short name

D-dimer

Frequently asked questions

Why might my doctor order a D-dimer test?
Your doctor may order this test to check for signs of blood clots, especially if you have symptoms like swelling in your legs, chest pain, or breathing difficulties, or if you’ve had recent surgery or a condition that increases your risk of clots.
What does a high or low D-dimer result mean?
A high D-dimer level suggests there may be recent clot activity, but it doesn’t confirm a diagnosis alone. A low or negative result usually means there’s little to no evidence of recent clotting, helping to rule out conditions like DVT or pulmonary embolism.
Can lifestyle changes affect D-dimer levels?
D-dimer levels are influenced by clotting activity, not typically by daily lifestyle factors like diet or exercise. However, conditions that increase clotting risk (such as dehydration, certain medications, or chronic diseases) may affect 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