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High INR Test Result: Care Instructions


You had a blood test to check how long it takes your blood to clot. This test is called a PT or prothrombin time test. The result of the test is called the INR level.

A high INR level can happen when you take warfarin (Coumadin). Warfarin helps prevent blood clots. To do this, it slows the amount of time it takes for your blood to clot. This raises your INR level. The INR goal for people who take warfarin is usually from 2 to 3.5. A value higher than 3.5 increases the risk of bleeding problems.

Many things can affect the way warfarin works. Some natural health products and other medicines can make warfarin work too well. That can raise the risk of bleeding. If you drink a lot of alcohol, that may raise your INR. And severe diarrhea or vomiting can also raise your INR.

The best way to lower your INR will depend on several things. In some cases, the doctor may have you stop taking warfarin for a few days. You may also be given other medicines to take.

You will need to be tested often to make sure your INR level is going down. You will also need to watch for signs of bleeding.

The doctor has checked you carefully, but problems can develop later. If you notice any problems or new symptoms, get medical treatment right away.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse advice line (811 in most provinces and territories) if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

How can you care for yourself at home?

Be careful with medicines and foods

  • Don't start or stop taking any medicines or natural health products unless you first talk to your doctor.
  • Keep the amount of vitamin K in your diet about the same from day to day. Do not suddenly eat a lot more or a lot less food that is rich in vitamin K than you usually do. Vitamin K affects how warfarin works and how your blood clots.
  • Limit your use of alcohol.

Avoid bleeding by preventing falls and injuries

  • Wear slippers or shoes with non-skid soles.
  • Remove throw rugs and clutter.
  • Rearrange furniture and electrical cords to keep them out of walking paths.
  • Keep stairways, porches, and outside walkways well lit. Use night-lights in hallways and washrooms.
  • Be extra careful when you work with sharp tools or knives.

When should you call for help?

Call 911 anytime you think you may need emergency care. For example, call if:

  • You passed out (lost consciousness).
  • You have signs of severe bleeding, such as:
    • A severe headache that is different from past headaches.
    • Vomiting blood or what looks like coffee grounds.
    • Passing maroon or very bloody stools.

Call your doctor or nurse advice line now or seek immediate medical care if:

  • You have unexpected bleeding, including:
    • Blood in stools or black stools that look like tar.
    • Blood in your urine.
    • Bruises or blood spots under the skin.
  • You feel dizzy or light-headed.

Watch closely for changes in your health, and be sure to contact your doctor or nurse advice line if:

  • You do not get better as expected.

Where can you learn more?

Go to

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Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.