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von Willebrand factor antigen (qualitative or quantitative plasma/serum measurement)

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

This test measures the amount of von Willebrand factor (VWF) in your blood, a protein that helps blood clot. It may be used to diagnose or monitor bleeding disorders or vascular conditions.

Quick summary

["VWF helps control bleeding; low levels may indicate inherited bleeding disorders or other conditions."]

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

Key facts at a glance

LOINC
48593-8
Short code
von Willebrand Pnl PPP
Synonyms
von Willebrand Pnl PPP
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

Why This Test Is Done

Doctors may order this test if you have symptoms like excessive bleeding (e.g., nosebleeds, heavy menstrual periods, or easy bruising), prolonged bleeding after surgery, or if you have a family history of bleeding disorders. It can also help evaluate conditions like von Willebrand disease or vascular issues.

How the Test Works

Blood is drawn and tested for VWF levels using an immunoassay method. This detects the protein’s presence and concentration in your plasma or serum. Results may be qualitative (yes/no presence) or quantitative (specific amount).

What to Expect Before the Test

No special preparation is needed, but inform your doctor about medications (e.g., blood thinners) or recent injuries. Avoid vigorous activity before the draw.

What the Results Mean

Results may show normal levels (within reference range), low levels (indicating potential bleeding disorders), or high levels (less common but may relate to certain conditions). Your doctor will interpret results in context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

VWF Antigen

Frequently asked questions

How does VWF deficiency affect bleeding?
Low von Willebrand factor levels can lead to bleeding disorders, such as von Willebrand disease, where blood clotting is impaired. This may cause prolonged bleeding from cuts, nosebleeds, or after surgeries. Doctors use these results to guide treatment, such as medications or blood transfusions.
Can high VWF levels be dangerous?
Elevated VWF levels are rare but may be associated with certain vascular diseases or inflammatory conditions. They’re less commonly linked to bleeding risks but should be monitored alongside other health factors.
What if my test results are abnormal?
If your results are abnormal, your doctor will discuss next steps, which may include further testing, lifestyle adjustments, or treatment plans tailored to your condition. Follow-up may involve monitoring symptoms or additional bloodwork.
  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