QS Study

Bleeding time (BT)

Definition: The time required for the stoppage of bleeding. It is a laboratory test to evaluate platelet function and the body’s capability to form a clot. The test involves making a puncture wound in an external area of the skin and monitoring the time needed for bleeding to stop.

Normal time: 1 – 6 minutes

Method of determination-

(i) Duke s method, and

(ii) Ivy’s method

Normal value Duke’s method – upto 8 min

Ivy’s method – upto 11 min

Fig: Ivy’s method

A bleeding time that is longer than normal is an abnormal result. The test should be stopped if the patient hasn’t stopped bleeding by 20-30 minutes. Bleeding time is longer when the normal function of platelets is impaired, or there are a lower-than-normal number of platelets in the blood.

Importance: In case of purpura bleeding time-prolonged. It is used most often to detect qualitative defects of platelets, such as Von Willebrand’s disease. The test helps identify people who have defects in their platelet function.