What does a high Prothrombin Time mean?

A value above the reference band means Prothrombin Time is outside the range typical for a healthy adult. A single reading is rarely conclusive on its own — what matters is the trend across draws and the other markers around it, which is why HealthOS reads the whole panel together rather than one number at a time.

Prothrombin Time: normal range and what it means

Q: How do I improve my Prothrombin Time?

Usually reported with INR, which standardises it between labs. Vitamin K intake affects it if you take warfarin.

Short answer: The normal prothrombin time range is 11 – 13.5 sec for adults. Labs differ a little, so also check the range printed on your report.

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Where does your prothrombin time sit?

Your prothrombin time

sec

Your result

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Information, not a diagnosis. Talk to a doctor about your result, and sooner if you feel unwell.

How quickly your blood clots.

Normal range

Adult reference range.

Low< 11 sec
Normal11 – 13.5 sec
High≥ 13.5 sec

818 sec

What it measures

How long your blood takes to clot along one particular pathway. It lengthens in liver disease, in vitamin K deficiency and on warfarin.

What moves it

Warfarin, vitamin K intake, liver function and fat absorption. The single most medication-sensitive marker on a routine panel.

How to bring it into range

Usually reported with INR, which standardises it between labs. Vitamin K intake affects it if you take warfarin.

How fast it responds

Days.

Also reported as: pt

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Common questions

What is the normal prothrombin time range?: The normal prothrombin time range is 11 – 13.5 sec for adults. Labs differ a little, so also check the range printed on your report.
What does a high Prothrombin Time mean?: A value above the reference band means Prothrombin Time is outside the range typical for a healthy adult. A single reading is rarely conclusive on its own — what matters is the trend across draws and the other markers around it, which is why HealthOS reads the whole panel together rather than one number at a time.
How do I improve my Prothrombin Time?: Usually reported with INR, which standardises it between labs. Vitamin K intake affects it if you take warfarin.

Related markers

INR

More in Coagulation

INR

Reference ranges are general-population guidance compiled from common clinical laboratories, not a diagnosis. Lab-to-lab ranges differ. Always read your results with your doctor.