This test measures the time it takes for bleeding to stop when skin is cut. It is used to evaluate the ability of blood to form blood clots to stop bleeding.
Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:
When and how often laboratory tests are done may depend on many factors. The timing of laboratory tests may rely on the results or completion of other tests, procedures, or treatments. Lab tests may be performed immediately in an emergency, or tests may be delayed as a condition is treated or monitored. A test may be suggested or become necessary when certain signs or symptoms appear.
Due to changes in the way your body naturally functions through the course of a day, lab tests may need to be performed at a certain time of day. If you have prepared for a test by changing your food or fluid intake, lab tests may be timed in accordance with those changes. Timing of tests may be based on increased and decreased levels of medications, drugs or other substances in the body.
The age or gender of the person being tested may affect when and how often a lab test is required. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Conditions that worsen and improve may also need frequent monitoring. Certain tests may be repeated to obtain a series of results, or tests may need to be repeated to confirm or disprove results. Timing and frequency of lab tests may vary if they are performed for professional or legal reasons.
Before the test is performed, tell the health care worker if you are allergic to latex, use anticoagulants or other blood-thinning medications, or have a medical condition that decreases blood circulation or causes excess bleeding. Also tell the health care worker if you have been nauseated, light-headed, or have fainted during blood tests in the past.
There are several ways that this test may be done. The healthcare worker will either make a small incision or lance your forearm or earlobe. Then the healthcare worker will swab blood from the area until it stops bleeding. A timer is used to measure the length of time it takes your blood to clot.
The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.
A bandage, cotton ball, or gauze may be placed on the area where the test was performed. You may be asked to apply pressure to the area. Avoid strenuous exercise immediately after your lab test. Contact your healthcare worker if you feel pain, see redness or swelling, or there is discharge from the test site.
Ask the healthcare worker to explain the risks of this test or procedure to you before it is performed.
Laboratory test results may vary depending on your age, gender, health history, the method used for the test, and many other factors. If your results are different from the results suggested below, this may not mean that you have a disease. Contact your healthcare worker if you have any questions. The following are considered to be normal results for this test:
Ask your healthcare worker how you will be informed of the test results. You may be asked to call for results, schedule an appointment to discuss results, or notified of results by mail. Follow up care varies depending on many factors related to your test. Sometimes there is no follow up after you have been notified of test results. At other times follow up may be suggested or necessary. Some examples of follow up care include changes to medication or treatment plans, referral to a specialist, more or less frequent monitoring, and additional tests or procedures. Talk with your healthcare worker about any concerns or questions you have regarding follow up care or instructions.
 Henry JB: Clinical Diagnosis and Management by Laboratory Methods, 20th ed. Saunders, 2001.
 Triplett DA: Laboratory diagnosis of von Willebrand's disease. Mayo Clin Proc 1991; 66(8):832-840.
 Fischbach FT & Dunning MB: A Manual of Laboratory and Diagnostic Tests, 7th ed. Lippincott Williams & Wilkins, Philadelphia, PA, USA, 2004.
 Tietz NW (Ed): Clinical Guide to Laboratory Tests, 3rd ed. W. B. Saunders, Philadelphia, PA, 1995.
 Kratz A, Ferraro M, Sluss PM, et al: Case records of the Massachusetts General Hospital: laboratory values. N Engl J Med 2004; 351(15):1549-1563.
 Rodgers RPC & Levin J: A critical reappraisal of the bleeding time. Seminars in thrombosis and hemostasis 1990; 16(No. 1):1-20.