International Normalised Ratio is also known as prothrombin time (PT). Your healthcare provider may order this test to determine how long it takes your blood to clot (blood clots look like small gel-like lumps. Usually, blood clots occur following an injury or a disease formation.
For example, if you're handling a knife and accidentally cut yourself, you will notice that the bleeding will stop after some time. Clotting is your body's way of preventing bleeding out.
Prothrombin is vital in blood clotting and the INR blood test result. Your liver produces prothrombin, one of the main proteins in blood clotting to stop bleeding.
INR stands for International Normalised Ratio and is measured with a blood test called PT-INR. PT (prothrombin time)-INR measures the time it takes for your blood to clot and determines if you're taking the right warfarin dose. If you have a low INR rate, you may be at risk of a blood clot, but a high INR may mean you may experience bleeding.
The normal INR rate is 2 – 3 but may vary between patients. Patients with a high risk of clotting may have a target range of 3 – 4, while patients with a higher bleeding risk may target 2 – 2.5.
The following tests make INR blood testing important.
This is the main reason most people need the INR blood test. These medications are preventive measures against blood clotting. This test helps your doctor determine the progress of your therapy and how to adjust your medication if necessary.
If you have a scheduled surgical procedure, your doctor will order the INR blood test to know how your blood clots. This ensures that you do not bleed out during or after your surgery.
A slow blood clotting time may indicate an underlying health issue.
Pulmonary embolism, or PE and deep vein thrombosis, or DVT, are common blood-clot-related conditions that an INR blood test can diagnose.
If you experience symptoms of liver disease, your doctor may order an INR test for more insight into the condition.
Generally, an INR test doesn't require special preparations. However, some people with specific conditions and those taking certain supplements or medications may need some preparations for the test. Your healthcare professional will inform you if you need any preparations for this test. If you think your doctor isn't aware of the medications you are taking, ensure you inform them.
The normal INR depends on the patient's condition, such as whether they are taking anticoagulants.
For patients taking anticoagulants, the normal range includes
For patients taking anticoagulants (acenocoumarol or warfarin), the normal range includes
Most people with high INR do not have symptoms, but it can result in serious bleeding. The bleeding may be obvious, like from a nosebleed or an injury, but it is important to know the symptoms that may occur from bleeding inside the body.
Ensure you get medical attention immediately if you experience any symptoms of high INR.
The first step is adhering to your doctor's instructions and taking your medications as prescribed. If you miss any dose, contact your healthcare professionals for instructions on what to do.
When filing your warfarin prescription, try filing it at the same pharmacy to get the same brand and remain consistent on it.
Your doctor also needs to be up to date on your medications because some medications interact with warfarin.
Watching your diet is also important, and be cautious of foods containing vitamin K because warfarin blocks vitamin K-dependent clotting factors. Increasing your vitamin K intake reduces the effectiveness of warfarin by lowering your INR levels and likely increasing your risk of blood clots. Foods containing high vitamin K levels include broccoli, Brussels sprouts and kale.
Other changes, such as starting a new diet or supplement, can fluctuate your INR.