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Prothrombin Time (PT) with INR

The Prothrombin Time with INR Test, often referred to as a PT with INR test, measures the amount of time it takes your blood to clot when various reagents are added.

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The Prothrombin Time with INR Test, often referred to as a PT with INR test, measures the amount of time it takes your blood to clot when various reagents are added. In order for your blood to clot properly, a series of proteins or clotting factors must react accordingly in a particular order. If one or more of these factors isn’t performing as it should, your body may struggle to stop itself from bleeding excessively. Knowing these figures can help physicians diagnose clotting or bleeding disorders. This Prothrombin Time with INR Test can be extremely valuable information should you ever require surgery.

How Does Our Prothrombin Time with INR Test Work?

Purchasing a Prothrombin Time Test through us at Priority Lab Testing is something you can do from the comfort of your home in a matter of minutes. You can browse our selection of tests, select the Prothrombin Time Test and any additional tests you would like, add them to the cart and complete payment. After you purchase the tests, you can then visit one of our 4,000 testing center locations throughout the country.

It is not necessary to make an appointment, and you can stop by at your convenience to have a member of our team draw a small blood sample to complete the test. The test itself is painless and quick, with most people out the door in a matter of minutes to go on with your day. After your blood is drawn the sample is sent to the lab for evaluation. You will receive a message indicating when your results are available for viewing within 24-72 hours following the test.

Common Symptoms That May Indicate a Clotting or Bleeding Disorder?

The prothrombin time test can help you identify if your blood is clotting as it should. This is helpful for individuals that may be at risk of bleeding or clotting disorders because of their medical history or who take medications that make them susceptible to developing clotting conditions or bleeding disorders. The prothrombin time test with INR will reveal whether your blood is clotting normally, too slowly or too quickly.

Indications that you may need a prothrombin time test with INR due to a clotting or bleeding disorder1 include:

  • Taking medications that affect blood clotting
  • Susceptibility to medical conditions that can lead to the development of blood clots
  • Planned surgery
  • Unexplained bruises or bleeding from minor lacerations
  • Recurrent nose bleeds
  • Bleeding gums
  • Unusually heavy menstrual flow

How to Interpret Your Prothrombin Time with INR Test Results?

When you receive your test results, you will want to know what the numbers and abbreviations mean. For a prothrombin test with INR, you will receive two separate results: PT for Prothrombin Time and INR2 for the international normalized ratio results.

The PT result will give you the time it takes for your blood to clot in the measurement of seconds. Along with your result, there will be a reference range to compare and whether your results fall within the low, normal or high range.

For the INR, you will receive your result and whether you fall in the low, normal or high range. Additionally, you will receive reference ranges for average results and the reference ranges that are applicable if you take any medication that could affect the calculations.

Prothrombin Time Test versus Standard Health Panel

The prothrombin time test is a useful evaluation in instances when you may have a procedure or surgery in the near future. It may also be beneficial to you to complete a Standard Health Panel to get an overview of your health before your medical procedure to understand your overall health at the moment and take precautions if necessary to facilitate your recovery.


  • A low prothrombin time with INR test will not tell you why your blood is not clotting properly but can give you insight if there is a potential problem when the results are abnormal. This can help you seek medical advice for further analysis into the underlying cause and how to treat it.

  • If your test results fall outside the normal range for the PT or INR results, you should consult a doctor for guidance. While this may not be an emergency, the test results may indicate you are at higher risk of complications due to bleeding or clotting problems with your blood.

  • If you know something is interfering with your body’s ability to clot properly, it can help your doctors take precautions and avoid unnecessary risks to your health. Furthermore, your doctor can help you determine if lifestyle changes, medications, or other interventions can help you reduce your risk of complications.

  1. https://www.hematology.org/education/patients/bleeding-disorders

  2. https://medlineplus.gov/lab-tests/prothrombin-time-test-and-inr-ptinr/