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The Antithrombin III Activity Test checks how well your blood’s natural clot blocker, called antithrombin, is working. You may also hear it called an antithrombin activity test or ATIII activity. If your doctor wants to look for a clotting tendency or to check medicine effects, you can book at participating labs on LabFinder.
This test, also called an antithrombin functional assay or AT activity, measures the function of antithrombin in a small blood sample. Low activity can raise the risk of unwanted clots. Normal or high activity helps show that the body’s natural anti clot system is working as expected.
Common reasons: a history of blood clots at a young age, clots that keep coming back, a strong family history of clots, checking for heparin resistance, or part of a thrombophilia workup that your doctor ordered. It may also be checked in some liver or kidney conditions.
You will check in and show your lab order. A staff member cleans a spot on your arm and draws a tube of blood. A small bandage is placed and you can leave right after. The visit usually takes 10 to 20 minutes.
Yes, this is a quick, routine blood draw and is considered very safe. You might feel a quick pinch, notice a small bruise, or feel a little lightheaded for a moment afterward, but those effects usually fade quickly. Be sure to tell the staff if you take blood thinners, have a bleeding disorder, or if you have fainted during blood draws before. They will take extra care to keep you comfortable.
No special fasting: this test usually does not require fasting unless your doctor added other labs. Share your medicines: tell the team about heparin or other blood thinners, and recent transfusions. Timing matters: testing during an active clot or right after major illness can affect results, so follow your doctor’s timing advice. Stay hydrated and bring ID and the order: this helps the draw go smoothly. Always follow any instructions from your doctor or the lab and bring prior results if available.
This test may help evaluate unexplained deep vein thrombosis, pulmonary embolism, inherited antithrombin deficiency, heparin resistance during treatment, liver disease that affects clotting proteins, kidney conditions like nephrotic syndrome, and widespread clotting problems such as DIC. Results are interpreted in context. Your doctor will review them with your history and symptoms before recommending next steps.
You can compare locations, see time slots, and book online at participating labs. It is easy to search for a convenient location in your area or by city or ZIP. Coverage varies by plan and provider, so please check with your insurance or ask the lab when you book.
Book on LabFinder: find a lab today on our lab finder and request a test doctor guided.
The information on this page and throughout the LabFinder website and mobile app is for general informational purposes only. It is not intended to serve as medical advice, diagnosis, or treatment. For personalized medical advice or specific health concerns, please consult your healthcare provider directly.
Booking a Antithrombin III Activity Test is easy using LabFinder. Just choose your location and enter your insurance information to find the closest Antithrombin III Activity Test near you.
To make a same-day appointment for a Antithrombin III Activity Test, just choose your location and your insurance information to find the closest Antithrombin III Activity Test location near you. If there's availability for a same-day appointment at a nearby lab location, then you will be able to book it easily through LabFinder.
LabFinder allows you to easily schedule a Antithrombin III Activity Test. You can search by location and insurance to easily book a Antithrombin III Activity Test near you.
LabFinder allows you to easily make an appointment for a Antithrombin III Activity Test online. To make an appointment for a Antithrombin III Activity Test online, just choose your location and your insurance information to find the closest Antithrombin III Activity Test near you.
Yes, you can get a Antithrombin III Activity Test without insurance. LabFinder allows you to search and select "Self-Pay" when booking a Antithrombin III Activity Test. While pricing for the test may not be immediately available, please check by calling the lab company directly for pricing.
