Mountain West · Prothrombin Test: Prothrombin Time PT with INR
Prothrombin Test: Prothrombin Time PT with INR in Colorado
Prothrombin Test: Prothrombin Time PT with INR is a laboratory test you can request directly. The prothrombin time test with INR measures how long it takes your blood to clot and helps assess your clotting system.
Lab requirements in Colorado
Here is what you need before ordering and completing the Prothrombin Test: Prothrombin Time PT with INR in CO. Review each item and confirm the details with the collection lab.
- Physician's order
- Included. A physician's order is required for lab testing and is provided for you by our partner's physicians — no referral from your own doctor is needed.
- Fasting
- Some tests require fasting or avoiding certain foods or drinks beforehand. You will be informed when you order — confirm the details with the collection lab.
- Preparation
- Preparation instructions vary depending on the reason for testing and the laboratory performing the collection. Always follow the specific instructions provided by your collection lab or…
- Sample & visit
- A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
- Identification
- Bring the lab requisition form from your account. The collection lab may also ask for a government-issued photo ID.
- Turnaround
- 1-3 business days
- Availability
- Our partner lab does not serve ND, RI, NY, NJ, MD or HI. Confirm availability for your location with the collection lab.
Before you go
- Order your test before visiting a lab, then use the requisition form in your account.
- Print the requisition form, or fax it to the lab directly from your account.
- No scheduling is needed — visit the collection lab during its normal business hours.
- A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
- Bring a government-issued photo ID in case the lab requests it.
- Results are posted to your secure account within 1–3 business days.
Requirements are summarized from our partner lab's published policies. Preparation and availability can change — confirm current instructions with the collection lab before your visit.
What this test is
The prothrombin time test evaluates the extrinsic and common pathways of blood coagulation by timing clot formation after adding tissue factor. The INR is a standardized ratio that allows results to be compared across different laboratories and reagent lots. Together, PT and INR are commonly used to monitor warfarin therapy and screen for bleeding or clotting disorders.
What it measures
- Prothrombin time (PT) — time in seconds for clot formation via the extrinsic and common pathways
- INR — standardized ratio that adjusts PT for reagent differences
- Clotting factor activity — reflects function of factors II, V, VII, X, and fibrinogen
What the test involves
A standard blood draw from a vein in your arm is used to collect the sample into a tube containing an anticoagulant. The sample is then processed in a laboratory to measure clot formation time.
Why it is often ordered
A clinician may order this test to monitor the effect of blood-thinning medications, to investigate unexplained bleeding or bruising, or as part of a pre-surgical evaluation. It can also help assess liver function or detect inherited or acquired clotting factor deficiencies.
Preparation
Preparation instructions vary depending on the reason for testing and the laboratory performing the collection. Always follow the specific instructions provided by your collection lab or ordering clinician.
How results are reported
Results are typically reported as the prothrombin time in seconds and the INR as a calculated ratio. Reference ranges and therapeutic targets vary by laboratory and clinical context, so your results should be interpreted by your clinician using the range provided with your report.
Before you go
- Whether any medications should be held before the draw
- If fasting or other dietary restrictions are needed
- When and how you will receive your results
Cities
Prothrombin Test: Prothrombin Time PT with INR in Colorado communities
Choose your city for local context and to order this test.