Above the range
Common causes of a high Prothrombin Time (PT)
- Warfarin therapy
- Vitamin K deficiency
- Liver disease
- DIC
Looking for the other direction? See what causes a low Prothrombin Time (PT).
All tests · Coagulation Studies · Prothrombin Time (PT)
Above the range
What causes a high Prothrombin Time (PT)?
Normal range 11-13.5 seconds. Specimen: Plasma (sodium citrate). See the full Prothrombin Time (PT) reference page for critical values and nursing considerations.
What is the normal range for Prothrombin Time (PT)?
The standard teaching reference range for Prothrombin Time (PT) is 11-13.5 seconds. This value is measured in plasma (sodium citrate).
| Specimen | Plasma (sodium citrate) |
|---|---|
| Conventional range | 11-13.5 seconds |
| SI range | 11-13.5 seconds |
| Critical value | > 30 seconds (marked bleeding risk) |
| Panel | Coagulation Studies |
Full details, including nursing considerations, on the Prothrombin Time (PT) normal range page. Reference ranges vary by laboratory, method, age, sex, and population - always use the range printed on the actual result.
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