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.