Prothrombin Time (PT) w/INR Blood Test
The Prothrombin Time w/ INR Blood Test is used to diagnose bleeding or clotting disorders and to determine if a medication that prevents blood clots is effective.
Also Known As:
Protime INR; Prothrombin Time Assay; Protime; PT; PT INR; Pro Time; INR; Prothrombin Time and International Normalized Ratio
Methodology:
Prothrombin time reagent containing thromboplastin and calcium chloride is mixed with the patient plasma and the time to clot formation is measured photo-optically. The calcium chloride overcomes the citrate anticoagulant and allows the tissue factor in the thromboplastin to initiate coagulation. The prolongation of the clotting time correlates with the degree of deficiency or inhibition of the extrinsic pathway factors.
Preparation:
No special preparation is required.
Test Results:
1-2 days. May take longer based on weather, holiday, or lab delays.
Walk-In Lab is prohibited from selling LabCorp tests to residents in the following states:NY, NJ, RI, MA, MD
Also Known As:
Protime INR; Prothrombin Time Assay; Protime; PT; PT INR; Pro Time; INR; Prothrombin Time and International Normalized Ratio
Methodology:
Photo-Optical Clot Detection
Preparation:
No special preparation is required.
Test Results:
1-2 days. May take longer based on weather, holiday, or lab delays.
Walk-In Lab is prohibited from selling Quest tests to residents in the following states:AZ, NY, NJ, RI
What is the purpose of this test?
Order this Prothrombin Time w/ INR Blood Test, which is used to diagnose bleeding or clotting disorders and to determine if a medication that prevents blood clots is effective. The liver produces a protein called prothrombin, one of the body's clotting factors. These clotting factors form a blood clot when an individual has a cut or injury that causes bleeding. The speed of clotting depends on the amount of clotting factors in the blood and their effectiveness. If the blood clots too slowly, the individual may experience excessive bleeding after an injury, while too-fast clotting can lead to dangerous clots in the veins or arteries.
A PT w/ INR Blood Test is most often used to:
- Monitor the effectiveness of warfarin medication. Warfarin is a commonly prescribed blood-thinning drug used to treat and prevent harmful blood clots. It is also sold under the brand name Coumadin.
- Discover the cause of unusual blood clotting.
- Discover the cause of any abnormal bleeding.
- Assess clotting function prior to surgery.
- Check for any potential liver problems.
When should I order a Prothrombin Time w/ INR Blood Test?
Individuals may order this test if they take warfarin regularly to ensure they take the correct dosage. If you are experiencing symptoms of a bleeding or clotting disorder and are not taking warfarin, it is highly recommended that you also undergo this test.
Signs indicating a bleeding disorder include:
- Experiencing heavy bleeding without a clear cause.
- Bruising easily
- Experiencing nosebleeds that are heavier than usual.
- Women may experience unusually heavy menstrual periods.
Symptoms of a clotting disorder include:
- Discomfort or sensitivity in your legs, such as pain or tenderness
- Swelling in the legs
- Redness or red streaks on the legs
- Trouble breathing
- Cough
- Chest pain
- Fast heartbeat
This test is sometimes ordered for patients before surgery to ensure normal clotting ability. Additionally, individuals can check out Walk-In Lab's other PT & PTT Blood Tests to help diagnose excessive or unexplained bleeding and bruising.
