What's this test for?

This test is ideal if you're experiencing unusual bruising, frequent nosebleeds, heavy menstrual periods, or bleeding that takes a long time to stop. It's also useful if you have a family history of bleeding problems and want to understand whether your blood is able to clot normally. Many people take this test to figure out if von Willebrand disease could explain their symptoms.

What happens after I get my results?

Your results will show up in your account along with the normal range so you can see exactly where your number falls. If your result is outside the normal range, next steps usually involve retesting or pairing this result with other clotting tests to get a fuller picture, and if you notice heavy or uncontrolled bleeding you should seek medical care right away. You can download a standard lab report directly from your account at any time. The trends feature also lets you track this value over time if you test again in the future.

Who should consider this test?

Anyone with a personal or family history of easy bruising, prolonged bleeding after surgery or dental work, heavy periods, or frequent nosebleeds should consider this test. It's also a smart choice if a relative has been diagnosed with von Willebrand disease, since the condition often runs in families. People preparing for surgery who have a history of bleeding issues may also want this information beforehand.

What symptoms indicate I may need this test?

Common signs include bruising easily without a clear cause, nosebleeds that are hard to stop, bleeding gums, heavy or prolonged menstrual bleeding, and excessive bleeding after cuts, surgery, or dental procedures. Some people also notice blood in their urine or stool. If these symptoms sound familiar, this test can help identify whether a clotting issue like von Willebrand disease is the cause.

When will I get my results?

Results are typically ready within about 7 days of your blood draw. Once ready, they'll be posted to your account where you can view and download them. You'll be able to see your specific value alongside the reference range to understand what it means.

What is von Willebrand Factor and why does it matter?

Von Willebrand Factor is a protein in your blood that helps platelets stick to injured blood vessels so bleeding can stop. This test, called Ristocetin Cofactor, checks how well that protein actually works, not just how much of it you have. If the protein doesn't function properly, even small cuts or injuries can lead to prolonged bleeding.

What does a low Ristocetin Cofactor result mean?

A low result suggests your von Willebrand Factor isn't working as well as it should, which can make it harder for your blood to clot properly. This is often linked to von Willebrand disease, an inherited bleeding condition. If your result is low, it's worth pairing this test with additional clotting studies and watching for symptoms like easy bruising or prolonged bleeding.

What causes an abnormal Ristocetin Cofactor result?

The most common cause of an abnormal result is an inherited form of von Willebrand disease, which affects how the protein functions from birth. Certain medications, liver conditions, or hormonal changes can also temporarily affect your result. Blood type can play a role too, since people with type O blood often have naturally lower von Willebrand Factor levels.

How often should I retest?

If your first result is normal and you have no bleeding symptoms, you likely won't need to retest unless new symptoms appear. If your result was abnormal or borderline, retesting after a few weeks or months can help confirm the finding, since levels can fluctuate due to stress, illness, or hormonal changes. Retesting is also useful before a planned surgery if you have a known bleeding history.

What should I do if my results are abnormal?

Start by reviewing the reference range in your report to see how far outside normal your result falls. Keep track of any bleeding symptoms you experience, such as bruising or prolonged bleeding, and consider retesting to confirm the result. If you experience heavy, uncontrolled, or unexplained bleeding, seek medical care promptly.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

Do you accept health insurance?

Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

Ristocetin Cofactor Test - Von Willebrand Disease Check

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

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