Prothrombin Time (INR) Blood Test
    Prothrombin Time (INR) Blood Test
    Prothrombin Time (INR) Blood Test
    Prothrombin Time (INR) Blood Test

Prothrombin Time (INR) Blood Test

£59

Need to monitor your blood clotting? This test measures international normalised ratio (INR) to assess how well your blood clots. It’s essential for people on warfarin therapy, those with liver disease, or anyone needing to check their clotting function.

You'll need to visit The Doctors Laboratory in London to collect your sample as the sample is not suitable for posting.

  • Results estimated in 3 working days
  • Convenient testing options
  • Bespoke doctor’s report
  • Free delivery

Includes INR, a key marker for blood clotting. For a more comprehensive assessment of clotting function, consider our Advanced Clotting Blood Test, which includes INR alongside additional clotting factors.

How do you want to take your sample?

  • Book a venous draw at a clinic   Venous
    +£35

    Visit one of our national clinic partners for a nurse to take your venous blood sample from a vein in your arm. We’ll email you instructions on how to book after we’ve processed your order.

18+ Only. T&Cs apply.

Find your nearest clinic
Key: You are here Appointment required Walk-in service
1
The Doctors Laboratory
Patient Reception ,76 Wimpole Street ,London ,W1G 9RT No appointment required
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You have the flexibility to choose what works best for you. Enjoy the comfort of having a friendly nurse visit your home for a quick blood draw, opt for a convenient visit to one of our nationwide partner clinics, or self-arrange a draw at a location that suits you.

Take control of your health with Medichecks – order your blood test today!

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What's in the test?

Clotting status

INR

Learn more

The international normalised ratio (INR) is a laboratory measurement of how long it takes for blood to form a clot. This can be useful to be able to determine the effects of anticoagulants such as warfarin on the clotting system.

How to prepare for your test

Test limitations

Reviews

FAQs

Who is a Prothrombin Time (INR) Blood Test for?

You can use our PT test if you are being treated with blood-thinning medication (anticoagulant) warfarin (Coumadin®) to monitor your treatment.

What does clotting status mean?

Your clotting cells (platelets) are produced in the bone marrow and help control bleeding. Sometimes too few platelets are produced or are destroyed too quickly, resulting in a condition known as thrombocytopenia. This can be caused by immune disorders, some medication, liver disease, or chronic bleeding. A high platelet count is called thrombocytosis and can be caused by several conditions, including bone marrow disorders, infection and inflammation. Read more about what blood is, the different blood types, and the main functions of blood in our blog: what is blood and what does it do?

What is a Prothrombin Time (INR) Blood Test?

Our Prothrombin Time (INR) Blood Test gives you your international normalized ratio (INR), which is calculated based on the results of your prothrombin time (PT) test. INR is a laboratory measurement of how long it takes for blood to form a clot.