Warfarin is a type of medicine known as an anticoagulant, or blood thinner.
It makes your blood flow through your veins more easily. This means your blood will be less likely to make a dangerous blood clot.
Warfarin is used to treat people who have had a previous blood clot, such as:
a blood clot in the leg (deep vein thrombosis, or DVT)

a blood clot in the lungs (pulmonary embolism)
It?s also used to prevent blood clots if you?re at high risk of having them in the future.
This includes people with:
an abnormal heartbeat (atrial fibrillation)

a replacement or mechanical heart valve

a blood clotting disorder, such as thrombophilia

a higher chance of having a blood clot after an operation
Warfarin is only available on prescription. It comes as tablets and as a liquid that you swallow.
It?s usual to take warfarin once a day, normally in the evening.

The main side effect of warfarin is bleeding more easily than normal, such as having nosebleeds, bleeding gums, heavier periods and bruising. This is most likely to happen in the first few weeks of treatment or if you?re unwell.

You need to have blood tests at least every 12 weeks while you?re taking warfarin to make sure your dose is right.

Expect your warfarin dose to go up or down. This is normal. The dose can depend on lots of different things, including what you eat and drink, what other medicines you?re taking, and if you become unwell.

Always carry your anticoagulant alert card with you. Show it to your doctor or dentist before you have any medical or dental procedures, including vaccinations and routine appointments with the dental hygienist.