Health article

Prothrombin Time Test and INR (PT/INR): MedlinePlus Medical Test

What happens during a PT/INR test?

The test may be done on a blood sample from a vein or a fingertip.

For a blood sample from a vein:

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

For a blood sample from a fingertip:

A fingertip test may be done in a provider’s office or in your home. If you are taking warfarin, your provider may recommend you test your blood regularly using an at-home PT/INR test kit. During this test, you or your provider will:

  • Use a small needle to puncture your fingertip
  • Collect a drop of blood and place it onto a test strip or other special instrument
  • Place the instrument or test strip into a device that calculates the results. At-home devices are small and lightweight.

If you are using an at-home test kit, you will need to review your results with your provider. Your provider will let you know how he or she would like to receive the results.

Source link