Prothrombin Time (PT/INR) Test

Prothrombin time test is used to calculate how well or how quickly the body forms clots in case of an injury. This may be done:

• In those suffering from bleeding disorders, where body bleeds excessively when injured
• In clotting disorders, where there are formation of excessive clots. 
• In those taking warfarin (anticoagulant) to assess its efficiency.
• Prior to surgeries to know the risk of bleeding.
• In liver disorders.

The Prothrombin Time (PT) test measures the time it takes for your blood plasma to form a clot. It essentially checks the efficiency of a specific pathway in your blood clotting system.

Prothrombin time test requires a blood sample. A tourniquet (elastic) band is placed tightly on the upper arm. The patient is then asked to make a fist. This helps in the build-up of blood filling the veins. The skin is disinfected before needle insertion and the blood sample is collected in vacutainer. 

Low PT indicates that the body is at a risk of forming excess blood clots which may mean a clotting disorder. High PT indicates delayed clotting which means that there is risk of bleeding excessively, occurs in cases of bleeding disorders. Vitamin K deficiency, liver disorders and certain medication like warfarin may also affect the PT.

There are no specific preparations required for the test. However, it is recommended that you consult with your healthcare provider before taking the test, as they may have specific instructions or recommendations based on your individual medical history and current health status. Mention the name of the medicine and its dose schedule in the test requisition form.

This test is similar to the other blood tests, so we need not worry. Any soreness or minor bruising at the blood collection site goes away with time.

Some foods rich in vitamin K can affect the results. Foods such as broccoli, chickpeas, green tea, soybean products, kale, chickpeas, turnip greens, asparagus, beef, and pork liver should be avoided.

PT (prothrombin time) and PTT (partial thromboplastin time) tests are both blood tests used to assess blood clotting, but they target different parts of the clotting cascade and provide information on distinct aspects of clotting function. PT test indirectly assesses prothrombin and other vitamin K-dependent clotting factors. While the PPT test evaluates a broader range of clotting factors compared to PT.

Haemophilia is an inherited bleeding disorder in which the blood fails to clot properly, thus leading to spontaneous bleeding.

There are 13 coagulation factors, out of which prothrombin (Factor II) is the most important.

A high PT level indicates that there is serious liver damage or cirrhosis.

• People with the following symptoms should do the PT test:
• Unusual heavy nose bleeds
• Unusual heavy menstrual periods in women
• Unexplained heavy bleeding or easy bruising
• Bleeding gums
• Leg pain, swelling, or redness
• Trouble breathing, cough, or chest pain
• Rapid heartbeat
• Swollen or painful joints
• Blood in the urine

• PT
• Pro Time
• Anticoagulant-prothrombin time
• Clotting time: protime
• INR
• International normalized ratio

The PT INR test is a blood test that measures the time taken for blood to clot and calculates the International Normalised Ratio (INR) to standardise results. It evaluates the extrinsic and common pathways of the blood clotting cascade.

The prothrombin time test is essential for monitoring warfarin therapy effectiveness and safety, diagnosing bleeding or clotting disorders, assessing liver function, and adjusting medication doses to prevent complications.

For individuals not on blood thinners, the normal PT INR test range is 11-13.5 seconds, with an INR between 0.8-1.1. For those on warfarin, the target INR is usually 2.0–3.0.

A high PT INR test result indicates slower blood clotting, which may be due to liver disease, vitamin K deficiency, bleeding disorders, or warfarin therapy effects. An INR > 3.0 may increase bleeding risk.

Abnormal PT INR blood test results can indicate bleeding disorders, liver disease, vitamin K deficiency, or issues with warfarin therapy, such as incorrect dosing or interactions with other medications, alcohol, or dietary changes.

The Prothrombin Time test can be performed at any age when necessary, such as for patients on warfarin, those with suspected bleeding or clotting disorders, or those being evaluated for liver disease.

Other tests that can be performed along with the PT INR test include partial thromboplastin time (PTT), complete blood count (CBC), and liver function tests.

The INR value is crucial for patients on warfarin therapy as it helps monitor medication effectiveness, adjust dosage, and prevent bleeding and clotting complications by ensuring the blood is neither too thin nor too thick.

The benefits of the Prothrombin Time test include monitoring warfarin therapy, diagnosing bleeding/clotting disorders, assessing liver function, and preventing complications by adjusting medication doses.

No, fasting is not necessary before the PT INR blood test. However, patients should inform their healthcare provider about any medications, supplements, or any dietary changes that might affect the results. 

Yes, Metropolis Healthcare offers the convenience of home sample collection for PT INR test. Ensuring your comfort and convenience without compromising the quality of the test. 

For patients who are on long-term warfarin therapy, home testing kits are available to monitor INR levels regularly. With proper training, patients can carry out the PT test from the comfort of their home. 

PT INR test results are available after 4 hours, depending on the day/time of sample collection. Metropolis Healthcare is committed to delivering timely and accurate results for all diagnostic tests.