PT Test (Prothrombin Time): Price, Purpose & Result [2024]
The PT (prothrombin time) or PT-INR Test is a blood test that measures the time it takes for blood to clot. Prothrombin is a clotting factor made in the liver. Doctors frequently use this to detect bleeding disorders and monitor the effectiveness of blood-thinning medications. It measures the level of activity of specific clotting-related proteins in the blood.
The standard method of reporting the results of the PT test is by using the international normalized ratio (INR). An INR (international normalized ratio) is a type of calculation based on PT test results. It compares the patient’s clotting time to that of an average, healthy person. Whereas a low INR suggests a quicker clotting time, a high INR predicts a longer clotting time. The price range of the PT test varies from Rs. 210 to Rs. 390 and in-home sample collection is also available.
Your doctor may recommend a Prothrombin test because of these main symptoms-
- excessive bleeding
- bruising easily
- prolonged bleeding after injury or surgery
- Fatigue
- Shortness of breath
- Abdominal pain
- Joint pain
- Swelling
PT Test Details in Brief
| Also Known As | PT Test, PT INR Test, Pro test, INR (International Normalized Ratio) Test, Coagulation Test, Clotting Time Test |
| Purpose | To measure the ability of blood to clot properly and assess the effectiveness of blood-thinning medications. |
| Preparation | No special preparation is required. |
| Fasting | Overnight fasting is preferred. A duly filled Coagulation Requisition Form is mandatory |
| Reporting Time | <24 hours |
| Cost | Rs. 210 to Rs. 390 |
PT Test Price
PT Test Price usually ranges from Rs 210 to Rs 390 on average. The actual price depends on the diagnostic centre and the city. Bookmerilab partners with more than 506 diagnostic centres across India. We provide a 10-50% discount on medical diagnostic tests.
Prices at Popular diagnostic centres
The table below lists the prices at some of the popular diagnostic centres.
| Name of Lab | Test Price |
|---|---|
| Redcliffe Labs | Rs 245 |
| Aarthi Scan | Rs 270 |
| City X-Ray | Rs 300 |
| Janta X-Ray | Rs 270 |
| Bharat X-Ray | Rs 228 |
| Dr Lal path labs | Rs 330 – Rs 390 |
| Prognosis Laboratories | Rs 210 |
| Vijaya Diagnostics | Rs 300 |
Cost in different cities
PT Test costs may vary depending on the city. The table below lists the city-wise prices. you can click on the city name link to get diagnostic centres list with their price and discount.
| City | Test Price |
|---|---|
| PT Test Price in Delhi | Rs 210 to Rs 333 |
| PT Test Price in Mumbai | Rs152 to Rs 390 |
| PT Test Price in Bangalore | Rs 245 to Rs 270 |
| PT Test Price in Hyderabad | Rs 162 to Rs 288 |
| PT Test Price in Gurgaon | Rs 245 to Rs 465 |
| PT Test Price in Chennai | Rs 245 to Rs 350 |
| PT Test Price in Kolkata | Rs 245 to Rs 360 |
| PT INR test cost in Pune | Rs 252 to Rs 330 |
| PT INR test cost in Chandigarh | Rs 245 to Rs 315 |
PT Test Purpose
- Monitoring the effectiveness of the blood-thinning medication.
- Diagnosing bleeding disorders.
- Evaluating the liver function.
- Assessing the risk of bleeding during surgery.
- Identifying the cause of unexplained bruising or bleeding.
- Monitoring clotting factors in patients with a history of blood clots.
- Assessing the risk of bleeding in pregnant women.
- Evaluating the effectiveness of vitamin K therapy.
Other clotting-related tests
- BT or Bleeding time measures the time taken by small blood vessels to stop bleeding. It is used to assess platelet function. It is usually between 1-9 minutes.
- CT or Clotting Times is the time taken to form a clot. It is usually between 8-15 minutes. The most commonly used test of clotting time is activated partial thromboplastin time (APTT) and prothrombin time (PT)
- APTT Test (Activated Partial thromboplastin time) measures the time taken by your blood to form a clot after an injury that causes bleeding.
- TT or Thrombin time is a measure of how long the blood’s plasma takes to form a clot. This test shows how long it takes fibrinogen (clotting factor) to turn into fibrin (this forms the clot).
What is the difference between Prothrombin Time and PTT
| Criteria | Partial Thromboplastin Time (PTT) | Prothrombin Time (PT) |
|---|---|---|
| Measures | The clotting ability of the intrinsic pathway of the coagulation cascade | The clotting ability of the extrinsic pathway of the coagulation cascade |
| Normal range | 25-35 seconds | 11-13.5 seconds |
| Measures | The time taken for fibrin clot formation | The time taken for fibrinogen to be converted to fibrin |
| Used to monitor | Heparin therapy and other clotting factor deficiencies | Warfarin therapy and other clotting factor deficiencies |
Preparation
- You might need to fast overnight.
- Let your doctor know if you use any supplements or medications, as some drugs may impact the outcome of the test.
- You should wear clothing that allows easy access to your arm since the healthcare provider will draw blood from a vein in your arm.
- Know what to say if you have a bleeding issue or are taking blood-thinning medication to the phlebotomist or healthcare practitioner.
- Occasionally, in order to get more reliable test results, your doctor may advise ceasing blood-thinning medication a few days before the procedure.
Procedure
It is a fairly simple diagnostic blood test. Below are the steps to draw a blood sample from the vein in your arm or hand-
- A technician (phlebotomist) may tie a tourniquet (elastic band) to your arm.
- The phlebotomist will locate your blood vessel.
- Then the site is cleaned with spirit.
- A Needle is inserted into your vein to draw the blood.
- The blood sample is then withdrawn into a syringe or a vial.
- Cotton is placed on the puncture site with mild pressure till the bleeding stops.
- A small band-aid is then placed, which may be removed after an hour.
The entire procedure takes only a few minutes.
Risk
It is a very simple and safe test. The risks involved are the same as that of any other blood test. These include-
- Infection at the puncture site if proper sterilization protocol is not followed and the needle is contaminated. This is, however, very rare. You may ensure that your phlebotomist takes out the needle in front of you from a sterile pack.
- Multiple pricks if the blood vessel is not easily found
- Excessive bleeding at the puncture site- Please inform your healthcare provider if you are taking any blood thinners or have any bleeding disorders.
- Light-headedness due to stress or heavy bleeding.
Minor pain and bruising that might occur will resolve on their own in a very short time.
PT Test Result & Interpretation
The Prothrombin Time (PT) test results are typically presented as an International Normalised Ratio (INR).
INR Calculation
The WHO gives the standard calculation formula for finding INR. It is calculated as a ratio of the patient’s Prothrombin to a control Prothrombin standardised for the test.
INR = Patient PT ÷ Control PT.
Result Interpretation
Normal Range: INR is typically around 0.8 to 1.1., while the normal range for PT is between 11 and 13.5 seconds.
High INR: A high INR means that the blood is clotting more slowly than is typical, which may signal a danger of bleeding and can occur in the following situations-
- Liver disease
- Vitamin K deficiency
- Warfarin therapy
- Disseminated intravascular coagulation (DIC)
- Inherited bleeding disorders such as haemophilia
Low INR: The blood is clotting too quickly when the INR is low, which may signal a blood clot risk. A lack of clotting factors is usually responsible and may be seen in the following conditions-
- Deep vein thrombosis (DVT)
- Pulmonary embolism (PE)
- Atrial fibrillation
- Antiphospholipid syndrome (APLA Test)
- Liver disease
An irregular range: It could be a sign of a medical problem such as a bleeding disorder. Your healthcare professional will interpret the test results in conjunction with other clinical data to determine the underlying reason and, if appropriate, devise a treatment strategy.
Normal Range Chart
| PT/INR | PT Range (in seconds) | Interpretation |
|---|---|---|
| 0.8 to 1.1 | 11 to 13.5 | Normal |
| >1.1 | >13.5 | High Risk of bleeding (Slow blood clotting) |
| <0.8 | <11 | Low Risk of Bleeding (Higher risk of clot formation) |
Clottings changes During pregnancy
The changes in the Prothrombin level in pregnant women are depicted in the following table.
| Units | Non-pregnant adult | First trimester | second trimester | third trimester |
|---|---|---|---|---|
| Prothrombin plasma time (in seconds) | 12.7 to 15.4 | 9.7 to 13.5 | 9.5 to 13.4 | 9.6 to 12.9 |
PT Test Sample Report
Limitations
- Limited evaluation of clotting factors: This test mainly evaluates the activity of clotting factors II, V, VII, and X. Other clotting factors, such as VIII and IX, are not directly assessed by the test.
- Interference from medications: It can be affected by certain medications, such as anticoagulants like warfarin or heparin. This can make it difficult to interpret the results of the test.
- Variable results: The Prothrombin time test can produce variable results depending on the laboratory performing the test, the reagents used, and the calibration of the equipment.
- Lack of sensitivity: It may not be sensitive enough to detect subtle changes in clotting function. Other tests, such as the activated partial thromboplastin time (aPTT), may be more sensitive in detecting certain bleeding disorders.
Conclusion
In conclusion, healthcare providers can use the Prothrombin Time (PT) test as a crucial diagnostic tool to detect bleeding disorders, assess liver health, and monitor the effectiveness of blood-thinning medications. Although it is a simple and low-risk procedure, the test can yield important information that can inform treatment choices and enhance patient outcomes.
Patients may feel more knowledgeable and in control of their healthcare decisions if they are aware of the PT test’s purpose, requirements, and potential risks. If your healthcare practitioner advises you to do a PT test, make sure to follow any pre-test instructions carefully and discuss any concerns you may have with them.
FAQs
It is a blood test that measures how long it takes for blood to clot in response to certain chemicals.
To assess the ability of the blood to clot, monitor the effectiveness of the blood-thinning medication, and diagnose bleeding disorders.
A healthcare provider will collect a blood sample from a vein in the arm and send it to a laboratory for analysis.
Bleeding, infection, or bruising at the site where the needle is inserted, as well as a small risk of excessive bleeding or hematoma formation.
Certain medications, such as blood-thinning medication, and medical conditions that affect clotting ability, such as liver disease.
The results are reported as an International Normalised Ratio (INR), which can indicate the risk of bleeding or blood clots.
The healthcare provider will interpret the test results in conjunction with other clinical information to determine the underlying cause of any abnormalities and develop an appropriate treatment plan if necessary.
How To Book a Prothrombin Time Test?
Dr Garima Saroj
Dr Garima Saroj is a dentist from Manipal college of dental sciences. She has previously worked at ESIC dental college and hospital Delhi and Dentecare multispecialty dental clinic Gurugram. She has a passion for writing for patient education and awareness.