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

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.

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.

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

This test helps diagnose bleeding problems.

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

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

• Blood vessel defect
• Platelet aggregation defect
• Thrombocytopenia (low platelet count)

Additional conditions under which the test may be performed:

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

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

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.