Why is Antithrombin III Low? Causes, Symptoms, and What to Do
Learn about low Antithrombin III levels, their causes, symptoms, and when to consult a doctor.
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is below the typical adult range (80–120 %).
is within the typical adult range (80–120 %).
is above the typical adult range (80–120 %).
This number is very far from the usual range - check which unit your report uses.
A value this far outside the range is worth discussing with your doctor today.
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See it next to the rest of your report - upload it for a free, private explanationFree. Sign up with your email - no password, we send you a code.Antithrombin III is a protein in your blood that helps prevent excessive clotting. It's important because it acts as a natural anticoagulant, keeping clotting in check. When Antithrombin III levels are low, it can lead to an increased risk of abnormal blood clots, a condition known as thrombophilia.
What is Antithrombin III?
Antithrombin III is a protein produced by the liver that plays a crucial role in regulating blood clotting. It works by inactivating several enzymes in the clotting process, including thrombin. The typical range for Antithrombin III activity in adults is 80 to 120%. When levels fall below this range, it can indicate a deficiency which increases the risk of developing blood clots.
Causes of Low Antithrombin III Levels
There are several reasons why Antithrombin III levels might be low. Some people are born with a genetic deficiency, which is a rare condition. Acquired causes include liver disease, as the liver is responsible for producing Antithrombin III, and certain medications like heparin can decrease its levels. Additionally, conditions such as nephrotic syndrome, where the kidneys leak proteins into the urine, can also result in lower Antithrombin III levels.
Symptoms of Low Antithrombin III
Low levels of Antithrombin III themselves do not cause symptoms, but the condition can lead to symptoms associated with blood clots. These may include swelling, pain, redness in a limb (often the leg), or sudden shortness of breath if a clot travels to the lungs. If you experience these symptoms, it is important to seek medical attention.
How is Low Antithrombin III Diagnosed?
If a doctor suspects a problem with blood clotting, they may order a blood test to measure Antithrombin III levels. This test will show whether your levels are within the typical adult range of 80 to 120%. If your levels are below this range, further investigation may be needed to determine the underlying cause.
Frequently asked questions
What happens if my Antithrombin III level is low? Low Antithrombin III levels can increase the risk of developing blood clots, which can lead to serious conditions like deep vein thrombosis or pulmonary embolism.
Can low Antithrombin III levels be treated? Yes, treatment depends on the underlying cause. It might include medication to prevent clots, lifestyle changes, or addressing any underlying medical conditions.
Is low Antithrombin III level hereditary? It can be. Some people inherit a genetic deficiency, making them more prone to low levels and related complications.
When to see a doctor
If you have a family history of blood clotting disorders, or if you experience symptoms such as unexplained swelling, pain, or shortness of breath, it is important to consult a healthcare professional. They can perform the necessary tests to determine if a low Antithrombin III level is a concern for you.
Disclaimer: This article provides general information and is not a substitute for professional medical advice. Always consult with your healthcare provider for decisions about your health.