Blood test

Low INR in a blood test

Blood test
>
Low INR in a blood test
Last update: 28/05/2021

What is low INR in a blood test called?

  • Low INR

What is the normal INR in a blood test?

If you need to know which are the INR reference ranges or you require more information about INR in a blood test, you can visit normal INR in a blood test.

What does a low INR in a blood test mean?

A low level of INR (International Normalized Ratio) shows a decrease in the time necessary to complete the clotting process. When there is a hemorrhage, the clotting process is activated to stop the bleeding. Therefore, the hemorrhages are stopped quickly.

This could be interpreted as a positive sign. However, it usually means an increase in the probability to develop a clot.

The INR below the normal range does not have any clinical meaning. In many cases, it is a consequence of laboratory errors. For this reason, it is convenient to repeat the blood test to confirm the value.

  • Mild INR decrease (< 0.9 in adults):

    A low INR value in a blood test increases the probability of suffering thrombosis. Anyway, it does not give too much information for a diagnosis. Your doctor may ask to perform other clotting tests to study if there is a real disorder.

Which factors can reduce the INR in a blood test?

There are some circumstances and drugs than can reduce your INR in a blood test:

  • Vitamin k excess intake
  • Pregnancy
  • Fresh frozen plasma transfusion
  • Drugs
    • Antacids
      • Sucralfate
    • Oral Contraceptives
    • Antidepressant
      • Colestyramine
    • Antiepileptic drugs
      • Carbamazepine
    • Antifungal
      • Griseofulvin
    • Antipsychotics
      • Haloperidol
    • Antituberculars
      • Rifampicin
    • Barbiturate
      • Glutethimide

Which diseases can reduce your INR in a blood test?

The most common diseases why the INR can be lower than normal are:

  • Thrombophlebitis

    What can I do to increase the INR in a blood test?

    To increase the INR values in a blood test you can follow the next tips:

    • Diet: Try to reduce the intake of food rich in vitamin K. You should reduce the intake of green leafy vegetables such as broccoli, kale or Brussels sprouts and some other foods high in vitamin K like chickpeas.
    • Medication: Your doctor may prescribe you anticoagulants such as warfarin (Coumadin) or acenocoumerol to avoid thrombosis if he considers it appropriate.

    Where can I find more information about INR in a blood test?

    You can visit our pages about:

    Which values are considered a low INR in a blood test?

    The following values are considered to be above the normal range:

    IMPORTANT: These levels are expressed in units. They are an example of a healthy man/woman of about 40 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

    INR
    Mild INR decrease
    0.89 0.88 0.87 0.86 0.85 0.84 0.83 0.82
    0.81 0.8 0.79 0.78 0.77 0.76 0.75 0.74
    0.73 0.72 0.71 0.7 0.69 0.68 0.67 0.66
    0.65 0.64 0.63 0.62 0.61 0.6 0.59 0.58
    0.57 0.56 0.55 0.54 0.53 0.52 0.51 0.5
    0.49 0.48 0.47 0.46 0.45 0.44 0.43 0.42
    0.41 0.4 0.39 0.38 0.37 0.36 0.35 0.34
    0.33 0.32 0.31 0.3     
    Medically reviewed by our Medical staff on 28/05/2021

    Bibliography

    • A Manual of Laboratory and Diagnostic Test. 9th edition. Frances Fischbach. Marshall B. Dunning III. 2014. Pag 159. ISBN-10: 1451190891.
    • Concise Book of Medical Laboratory Technology: Methods and Interpretations. 2nd Edition. 2015. Ramnik Sood. ISBN: 978-93-5152-333-8. Pag. 282.
    • Laboratory tests and diagnostic procedures with nursing diagnoses (8th ed), Jane Vincent Corbett, Angela Denise Banks, ISBN: 978-0-13-237332-6, Pag. 300.
    • Essentials of Medical Laboratory Practice. Constance L. Lieseke, Elizabeth A. Zeibig. 2012. ISBN: 978-0-8036-1899-2 Pag: 319.
    • Common Terminology Criteria for Adverse Events (CTCAE). Version 5.0.Published: November 27, 2017. U.S. Department of health and human Services. Available on: https://ctep.cancer.gov

    Show more

    Rating Overview

    Share your thoughts about this content
    Poor
    Excellent

    E-mail (Optional):
    Add a review