What's this test for?

This test is ideal if you're experiencing unexplained bruising, prolonged bleeding after surgery or dental work, or heavy bleeding that doesn't seem to stop as quickly as it should. It's also useful if a routine blood clotting screen (called an aPTT) came back longer than expected and needs further investigation. People with Ashkenazi Jewish heritage may also consider this test since Factor XI deficiency is more common in that population.

What's included in this test?

This test measures how well Factor XI, one of the proteins your body uses to form blood clots, is working. Checking this single clotting factor helps explain unusual bleeding patterns or an abnormal clotting screen result, since low activity can mean your blood takes longer to clot properly.

What happens after I get my results?

Your results will show up in your account with your Factor XI activity level and an explanation of what the normal range means. If your level is outside the expected range, the report will explain what that could mean and suggest reasonable next steps, such as repeat testing or additional clotting studies. You can download a standard lab report anytime from your account, and if you test again in the future, you'll be able to track your results over time using the trends feature.

When will I get my results?

Results are typically ready within about 7 days of your blood draw. This turnaround allows the lab to run the specialized clotting assay needed to measure Factor XI activity accurately. You'll get a notification once your results are posted to your account.

Who should consider this test?

Anyone with a personal or family history of unusual bleeding, bruising easily, or a previously abnormal aPTT result should consider this test. It's especially relevant for people of Ashkenazi Jewish descent, since Factor XI deficiency is more common in that group. It can also be useful before a planned surgery if there's a known bleeding tendency in the family.

What symptoms indicate I may need this test?

Watch for signs like nosebleeds that are hard to stop, heavy or prolonged menstrual bleeding, easy bruising, or bleeding that continues longer than expected after a cut, dental procedure, or surgery. Frequent bleeding gums can also be a clue. If you notice any of these along with a family history of bleeding problems, this test can help clarify what's going on.

What does high Factor XI mean?

Factor XI activity above the normal range is uncommon and usually isn't associated with a specific bleeding or clotting disorder on its own. It's typically not a cause for concern the way low levels are. If your report flags a high result, the explanation in your account will walk through whether any follow-up makes sense.

What does low Factor XI mean?

Low Factor XI activity means your blood may take longer to clot, which can lead to prolonged bleeding after injury, surgery, or dental work. Interestingly, the severity of low levels doesn't always match how much bleeding someone actually experiences, so a low number doesn't automatically mean serious problems. Simple precautions like informing anyone performing a procedure on you about your result and avoiding blood-thinning medications unnecessarily can help manage the risk.

What causes low Factor XI?

Low Factor XI is most often inherited, especially in people with Ashkenazi Jewish heritage, meaning it's something you're born with rather than something that develops later. Certain medications, like direct thrombin or Factor Xa inhibitors, can also cause a falsely low reading if taken shortly before testing. Occasionally, the body produces an inhibitor that interferes with Factor XI function, which additional testing like mixing studies can help sort out.

How often should I retest?

Since Factor XI deficiency is usually a lifelong inherited trait, you generally don't need to retest often once a baseline result is established. Retesting may make sense if you're preparing for surgery, experiencing new bleeding symptoms, or if your first result was affected by medication you were taking at the time. If your first test showed an inhibitor pattern, follow-up testing may be recommended to clarify the cause.

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.

Factor XI Clotting Test - Bleeding Disorder 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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