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Bleeding Time

Definition

Bleeding time is a blood test that looks at how fast small blood vessels close to stop you from bleeding.

How the test is performed

A blood pressure cuff inflates around your upper arm. While on the cuff is on your arm, the health care provider makes two small cuts on the lower arm. They are just just deep enough to cause a tiny amount of bleeding.

The blood pressure cuff is immediately deflated. Blotting paper is touched to the cuts every 30 seconds until the bleeding stops. The health care provider records the time it takes for the cuts to stop bleeding.

How to prepare for the test

Certain medications may change the test results. Always tell your doctor what medications you are taking, even over-the-counter drugs. Drugs that may increase bleeding times include dextran, nonsteroidal anti-inflammatory drugs (NSAIDs), and salicylates (including aspirin).

Your doctor may tell you to stop taking certain medicines a few days before the test. Never stop taking medicine without first talking to your doctor.

How the test will feel

The tiny cuts are very shallow. Most people say it feels like a skin scratch.

Why the test is performed

This test helps diagnose bleeding problems.

Normal Values

Bleeding normally stops within 1 to 9 minutes. However, values may vary from lab to lab.

What abnormal results mean

Longer-than-normal bleeding time may be due to:

Additional conditions under which the test may be performed:

  • Acquired platelet function defect
  • Congenital platelet function defects
  • Primary thrombocythemia
  • Von Willebrand's disease

What the risks are

There is a very slight risk of infection where the skin is broken. Excessive bleeding is rare.

References

Schafer A. Hemorrhagic disorders: Approach to the patient with bleeding and thrombosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 178.

Review Date: 3/2/2009

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Information developed by A.D.A.M., Inc. regarding tests and test results may not directly correspond with information provided by UCSF Medical Center. Please discuss with your doctor any questions or concerns you may have.