Appointments

866.320.4573

Request an Appointment

Questions

800.223.2273

Contact us with Questions

Expand Content

Blood Tests for Those Taking Anticoagulants (Blood Thinners)

When taking an anticoagulant, it is important to have your blood tested for bleeding times to ensure you are taking your medications safely and not at increased risk for bleeding

Prothrombin Time (PT)

Normal range for an adult: 9.9-13 seconds

Preparation

This test may be measured any time of the day without fasting.

PT is a test to determine how fast it takes for your blood to clot. Usually when taking a "blood thinner," such as warfarin (Coumadin), the desired PT is about one and a half times the normal PT. When checking PT, your doctor will receive the results and let you know if you are taking the correct amount of blood thinner medication.

International Normalized Ratio (INR)

Normal level for an adult: 0.9 – 1.2. Your doctor will determine your therapeutic range.

Preparation

This test may be measured any time of the day without fasting.

INR is tested for those on anticoagulant medications to prevent stroke, embolism and heart attack.

Reviewed: 09/13

This information is about testing and procedures and may include instructions specific to Cleveland Clinic. Please consult your physician for information pertaining to your testing.

Talk to a Nurse: Mon. - Fri., 8:30 a.m. - 4 p.m. (ET)

Call a Heart & Vascular Nurse locally 216.445.9288 or toll-free 866.289.6911.

Schedule an Appointment

Toll-free 800.659.7822

This information is provided by Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition.

© Copyright 2014 Cleveland Clinic. All rights reserved.

HealthHub from Cleveland Clinic

Read the Latest from Our Experts About cctopics » Heart & Vascular Health
High Blood Pressure? Don’t Take Vitamin D for It (Video)
11/20/14 8:31 a.m.
Sellers of vitamin D claim the nutrient can lower your blood pressure. But don’t believe the hype. Despite claims from the nutrition industry and non-medical personnel abou...
by Steven Nissen, MD
When Your Heart Stents Narrow, Brachytherapy Can Help
11/19/14 8:22 a.m.
Cardiac stents are an effective, nonsurgical way of holding a narrowed or blocked artery open to increase blood...
A Post ER Follow-Up Could Save Your Life
11/17/14 8:39 a.m.
Even if Emergency Room doctors say you didn’t actually have a heart attack, that doesn’t mean you h...
Recipe: Low-Fat Crunchy Pumpkin Pie
11/14/14 7:00 a.m.
This low-fat crunchy pumpkin pie uses only a small amount of oil in the crust and skim milk in the filling to m...
Varicose Veins: Not Just an Older Woman’s Problem
11/13/14 8:13 a.m.
You might think of varicose veins as an older woman’s problem, but it may actually have more to do with your li...