About this test
APTT measures how long blood takes to clot through a different pathway from PT/INR. Together, the two tests give a fuller picture of how well your blood clots.
Why it is done
- Before surgery or a procedure, to check clotting.
- To investigate unexplained or prolonged bleeding.
- To monitor treatment with heparin, when advised by the doctor.
Preparation
No fasting is needed. Please tell us about any blood-thinning medicines you take. Do not stop any medicine unless your doctor tells you to.
This information is general and is not medical advice. Please speak to your doctor about your results and treatment.