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D-dimer, plasma mass concentration

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

This test measures the level of D-dimer, a protein fragment produced when blood clots dissolve. It helps assess the risk of blood clots or conditions like deep vein thrombosis (DVT) or pulmonary embolism.

Quick summary

["D-dimer helps doctors evaluate whether you may have a blood clot or clot-related issues."]

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

Key facts at a glance

LOINC
91556-1
Short code
D Dimer Bld IA.DDU-mCnc
Synonyms
D Dimer Bld IA.DDU-mCnc
Category
coagulation
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia-ddu
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order a D-dimer test if you have symptoms like leg swelling, pain, or shortness of breath that could suggest a blood clot. It may also be used to rule out conditions like deep vein thrombosis (DVT) or pulmonary embolism, especially when combined with other tests or imaging.

What Does a High or Low Level Mean?

A high D-dimer level often indicates recent clot formation and may prompt further testing or treatment for conditions like DVT or pulmonary embolism. A low level suggests a reduced risk of these conditions, but it doesn’t rule them out entirely.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The blood is then processed to measure the D-dimer concentration using a specialized laboratory method.

What Are Possible Results?

Results are qualitative (qualitative results indicate whether the level is above or below a threshold rather than a specific numeric value). A positive result suggests a higher likelihood of clot-related conditions, while a negative result suggests a lower likelihood.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

D-dimer

Frequently asked questions

What Does It Mean If My Results Are Abnormal?
If your D-dimer test is positive, your doctor may recommend additional tests, such as imaging studies (like an ultrasound or CT scan), to confirm or rule out blood clots. If negative, further evaluation may still be needed depending on your symptoms and medical history.
Can I Take Anything Before the Test?
No special preparation is usually needed, but always follow your doctor’s instructions. Avoid taking blood-thinning medications (like warfarin or aspirin) without consulting your doctor, as they can affect results.
How Long Does It Take to Get Results?
Results are typically available within a few hours to a couple of days, depending on your lab’s processing time.
  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