Platelet Aggregation with Collagen by Impedance

This test evaluates how your platelets clump together when they are stimulated by collagen, using an electrical impedance method performed on whole blood. It detects the change in electrical resistance created as platelets adhere to sensor wires and aggregate after activation.

Collagen is a natural trigger that platelets encounter at an injured blood vessel, so this assay mimics an early step in normal clot formation. It is often performed alongside other platelet activation studies to provide a fuller picture of overall platelet function.

Clinicians use this test to investigate easy bruising, frequent nosebleeds, heavy menstrual bleeding, or unexpected bleeding during or after procedures when a platelet problem is suspected. It helps assess inherited or acquired platelet function disorders and can contribute to the evaluation of von Willebrand disease. It is also used to check the effect of antiplatelet medicines.

Results can inform decisions about further testing, the timing of surgeries or dental work, and how best to manage medications. An abnormal result on its own does not diagnose a condition, but it points to patterns that, combined with your history, examination, and other laboratory findings, help clarify bleeding risk or how you respond to treatment.

A lower than expected response suggests reduced platelet aggregation. This can happen if you recently took certain medicines, if your platelet count is low, with some systemic illnesses, or due to specific inherited platelet signaling problems. Issues with how the sample was collected or handled can also reduce the response, so your care team may confirm unexpected findings with a repeat test.

A higher than expected response may reflect increased platelet reactivity or normal variation. Your clinician will interpret your result together with other agonist studies, your complete blood count, and your bleeding history. If results are unclear or do not match your symptoms, follow-up may include repeating the test, adjusting medication timing, or ordering additional studies. Seek urgent medical attention if you have ongoing significant bleeding or symptoms that worry you.