Blood test

Low prothrombin time in a blood test

Blood test
>
Low prothrombin time in a blood test
Last update: 19/05/2021

What is low prothrombin time in a blood test called?

  • Low Prothrombin time (PT)

What is the normal prothrombin time in a blood test?

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

What does a low prothrombin time in a blood test mean?

A low prothrombin time (PT) in a blood test has no clinical meaning. It is not used for the diagnosis of any disease.

If the prothrombin time (PT) is low, it means that when there is a hemorrhage the clot is formed very fast and the bleeding stops quickly.

This may be positive, but it may be related to a hypercoagulable state where the blood clots too much and increase the risk of blood clot formation in veins.

In practice, most cases are usually to error in the measurement so if the prothrombin time is low it is recommended to perform a new test again to exclude this possibility.

  • Mild prothrombin time decrease (< 11 seconds in adults):

    A mild prothrombin time (PT) decrease it is not a clue to the diagnosis of any disease. If your doctor considers it appropriate because he suspect a hypercoagulability disorder, it may require additional screen tests.

Which factors can reduce the prothrombin time in a blood test?

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

  • Vitamin k excess intake
  • Pregnancy
  • Fresh frozen plasma transfusion
  • Drugs
    • Oral Contraceptives
    • Antiepileptic drugs
      • Carbamazepine
    • Antifungal
      • Griseofulvin
    • Barbiturate
      • Glutethimide

Which diseases can reduce your prothrombin time in a blood test?

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

  • Thrombophlebitis

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

    A prothrombin time (PT) decrease may be due to an excessive vitamin K intake. For this reason, you may try to reduce your vitamin K intake. The following foods are rich in vitamin K and you should reduce the intake: leafy greens (sprouts, kale or broccoli), cucumbers, asparagus or chickpeas.

    If your doctor considers it appropriate he can prescribe you oral anticoagulants (warfarin) to avoid the clot formation. They increase the prothrombin time as a consequence.

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

    You can visit our pages about:

    Which values are considered a low prothrombin time in a blood test?

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

    IMPORTANT: These levels are expressed in seconds. 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.

    Prothrombin time
    Mild prothrombin time (PT) decrease
    10.9 s10.8 s10.7 s10.6 s10.5 s10.4 s10.3 s10.2 s
    10.1 s10 s9.9 s9.8 s9.7 s9.6 s9.5 s9.4 s
    9.3 s9.2 s9.1 s9 s8.9 s8.8 s8.7 s8.6 s
    8.5 s8.4 s8.3 s8.2 s8.1 s8 s7.9 s7.8 s
    7.7 s7.6 s7.5 s7.4 s7.3 s7.2 s7.1 s7 s
    6.9 s6.8 s6.7 s6.6 s6.5 s6.4 s6.3 s6.2 s
    6.1 s6 s      
    Medically reviewed by our Medical staff on 19/05/2021

    Bibliography

    • Concise Book of Medical Laboratory Technology: Methods and Interpretations. 2nd Edition. 2015. Ramnik Sood. ISBN: 978-93-5152-333-8. Pag. 283.
    • A Manual of Laboratory and Diagnostic Test. 9th edition. Frances Fischbach. Marshall B. Dunning III. 2014. Pag 158. ISBN-10: 1451190891.
    • 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.

    Show more

    Rating Overview

    Share your thoughts about this content
    Poor
    Excellent

    E-mail (Optional):
    Add a review