Prothrombin Time (PT)
Prothrombin Time (PT) measures how long it takes for your blood to clot. It evaluates the extrinsic and common pathways of the coagulation cascade.
Category: Coagulation
Also known as: pt, prothrombin time, pro time, protime, protrombinsko vreme
Reference range: 11–13.5 seconds (Source: ABIM)
Standard unit: seconds
High values may indicate
Prolonged PT may indicate liver disease, vitamin K deficiency, warfarin (blood thinner) therapy, disseminated intravascular coagulation (DIC), or clotting factor deficiencies.
Low values may indicate
Shortened PT is uncommon but may indicate a hypercoagulable state, high vitamin K intake, or use of certain medications.
Frequently asked questions
- What is a normal Prothrombin Time (PT) level?
- A typical reference range for Prothrombin Time (PT) is 11–13.5 seconds (source: ABIM). Reference ranges vary by laboratory, age, and sex, so always compare against the range on your own lab report.
- What units is Prothrombin Time (PT) measured in?
- Prothrombin Time (PT) is most commonly reported in seconds. Labs in different countries may use other units — you can convert between them with BloodId's blood test unit converter.
- Where do Prothrombin Time (PT) reference ranges come from?
- BloodId uses ABIM standard reference ranges and educational information from MedlinePlus (see our methodology). Reference ranges still vary by lab, age, and sex, so always compare against your own report.
- Can I track Prothrombin Time (PT) over time?
- Yes. Upload results from any lab and BloodId charts your Prothrombin Time (PT) over time against its reference range, so you can see whether the trend is rising, falling, or stable.
Related biomarkers
Source: MedlinePlus, U.S. National Library of Medicine
Analyze your Prothrombin Time (PT) with AI