Prothrombin Time Test
How long it takes blood to clot via the extrinsic pathway. Used to monitor warfarin therapy.
What is Prothrombin Time?
How long it takes blood to clot via the extrinsic pathway. Used to monitor warfarin therapy.
Prothrombin Time Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 11.0 – 13.5 seconds |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
What your Prothrombin Time result may mean
Often reflects warfarin therapy, vitamin K deficiency, or liver disease.
Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
Sources
Frequently asked
No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.
Ready to test your prothrombin time?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $23.99.