Overview

Warfarin (such as Coumadin) is a medicine that helps prevent blood clots. It is often called a blood thinner. Doctors give warfarin to reduce the risk of blood clots.

Warfarin slows the time it takes for your blood to clot. That means it can cause bleeding problems. So it's important to know how to take it safely.

Foods and other medicines can affect the way warfarin works. Some can make warfarin work too well, which can cause bleeding. Others can make it work poorly, so that it doesn't prevent clots very well.

You'll also need regular blood tests to check how long it takes for your blood to form a clot. Depending on the results, your doctor may adjust your dose of warfarin.