Description
Why It’s Done:
The aPTT test is ordered to:
• Evaluate unexplained bleeding or bruising
• Monitor anticoagulant therapy (especially unfractionated heparin)
• Diagnose clotting disorders such as hemophilia or von Willebrand disease
• Detect liver disease or vitamin K deficiency affecting clotting factors
• Screen for presence of lupus anticoagulant or other clotting inhibitors
Preparation:
• No special preparation is typically required.
• Inform your healthcare provider if you are taking any blood-thinning medications (e.g., heparin, warfarin) or supplements that affect clotting (e.g., aspirin, fish oil).
• Avoid excessive physical activity or trauma before the test.
• Blood is drawn via venipuncture from a vein, usually in the arm
