Bleeding time is a crude test of hemostasis. It indicates how well platelets interact with blood vessel walls to form blood clots. Bleeding time is used most often to detect qualitative defects of platelets. The bleeding time test is usually used on patients who have a history of prolonged bleeding after cuts, or who have a family history of bleeding disorders.
There are several methods to perform the bleeding time test:
- Ivy method: is the traditional format for this test. In the Ivy method, a blood pressure cuff is placed on the upper arm and inflated. A lancet or scalpel blade is used to make a stab wound on the underside of the forearm. The time from when the stab wound is made until all bleeding has stopped is measured and is called the bleeding time. Every 30 seconds, filter paper or a paper towel is used to draw off the blood. The test is finished when bleeding has stopped completely.
- Template method: a template is placed over the area to be stabbed and two incisions are made in the forearm using the template as a location guide.
- Duke method: a nick is made in an ear lobe or a fingertip is pricked to cause bleeding.
A normal bleeding time for the Ivy method is less than five minutes from the time of the stab until all bleeding from the wound stops. Some texts extend the normal range to eight minutes. Normal values for the template method range up to eight minutes, while for the modified template methods, up to 10 minutes is considered normal. Normal for the Duke method is three minutes. Classic bleeding time has become obsolete, definition and images are for academical purposes.
A series of pictures showing some aspects of the bleeding time test, as described in the text. Click on pictures to enlarge. (For image uses, please see Use of Content at Legal Information).
Sakariassen KS, Bolhuis PA, Blomback M, Thorell L, Blomback B, Sixma JJ. Association between bleeding time and platelet adherence to artery subendothelium. Thromb Haemost. 1984; 52: 144-7.
Rodgers RP, Levin J. Bleeding time revisited. Blood. 1992; 79: 2495-7.