17/08/2025
Bleeding Time (BT) test:
1. Objective
To measure the time taken for bleeding to stop after a standardized skin incision, assessing platelet function and capillary integrity.
2. Principle
A small, controlled cut is made on the skin (usually forearm or earlobe). The duration until bleeding stops is recorded. Prolonged bleeding time indicates platelet disorders, vascular defects, or certain medications (e.g., aspirin).
3. Materials
Sterile lancet or incision device
Stopwatch
Filter paper (to blot blood)
Spirit swab
Gloves
PPE (lab coat, mask)
4. Procedure (Duke’s Method – earlobe/finger prick)
1. Clean site with spirit swab.
2. Puncture earlobe or fingertip with sterile lancet.
3. Start stopwatch immediately.
4. Every 30 seconds, blot blood with filter paper (do not press the wound).
5. Stop timing when bleeding completely stops.
5. Result (Example)
Normal range:
Duke’s method: 1–3 minutes
Ivy method: 2–7 minutes
Prolonged BT: Thrombocytopenia, von Willebrand disease, platelet dysfunction, aspirin use.
6. Uses
Evaluate platelet function and primary hemostasis.
Screen for bleeding disorders.
7. Conclusion
Bleeding time is a simple bedside test for platelet function, but it is less commonly used today due to more precise platelet aggregation and clotting assays.
