Frequently asked questions

About anticoagulants

Anticoagulants are medicines that make it harder for blood clots to form. They can be prescribed for people who have atrial fibrillation (AF) to reduce the risk of having a stroke and for people who have had / may develop a blood clot in a blood vessel (thrombosis), or in their lungs (pulmonary embolism), to help reduce the risk of serious complications. They may also be prescribed for people who have a blood clotting disorder.1

If you cut yourself and start bleeding, the body activates a natural process that causes the blood to stick together (clotting) to stop the bleeding. This is a normal and healthy mechanism.2

However, in some people, blood clots can develop within the blood vessels when there is no external injury or bleeding, and block blood flow, which can potentially be harmful.2

For example, if you have AF, your heart can pump blood unevenly. Because the blood is not being pumped efficiently, it can sometimes pool and form a thick blood clot. If this occurs, a clot, or bits of a clot, can break loose and travel through the bloodstream. It may then block a blood vessel that leads to an organ or part of the body. If a clot blocks blood flow to the brain, it may cause a stroke – your doctor may prescribe medication to reduce this risk.3

Blood clots can also occur in other parts of the body, such as the lower leg, thigh or around the pelvis. This might occur if you suddenly become very inactive, for example if you have had a knee or hip replacement operation. This type of blood clot formation is sometimes known as a deep vein thrombosis (DVT). The clot stops or slows the normal flow of blood in the vein, leading to blood building up below the clot.2

Sometimes, a blood clot or part of one can break free and travel through the bloodstream into the lungs. This is known as a pulmonary embolism.2 These blood clots can have serious health complications, so doctors may prescribe an anticoagulant medication to help prevent these blood clots forming or, if you have already had one, from it happening again.1,2

There are several different types of treatments that can be taken at different times and in different ways (for example, tablets or injections). If your doctor feels that you need to take one, you can discuss the options with them.1 Healthcare teams provide specific guidance for each treatment and, in addition, there is an information leaflet inside the medication pack as a useful reminder.

Staying healthy while taking anticoagulants

It depends on the anticoagulant you are given, as some are affected by certain foods and drinks. 4 Your healthcare team should give you these details when you start your medication [(and the patient information leaflet inside your pack of tablets is also a useful source of information)].

It is very important to ask your doctor whether you can take other medicines with your anticoagulant. This includes both prescription and non-prescription medicines as well as supplements. This is because some other medicines can sometimes affect the way an anticoagulant works.4

Many people are concerned that they cannot exercise if they are taking anticoagulants, but it is good to do some exercise regularly, regardless of your medication.5 Talk to your healthcare team about what exercises are suitable for you.

All medicines can cause side effects, although not everybody gets them. Anticoagulants help to reduce your risk of blood clots, but they can also mean bruising and bleeding could happen more easily. Bleeding can be something you may see (e.g. nosebleed or from an injury) or something you may not (e.g. in your stomach or brain).1 If you feel unwell or have bleeding that does not stop, you should contact your healthcare team straightaway for their advice. Remember that you may be able to contact them by telephone or online to avoid face-to-face contact.

More details about possible side effects can be found in the information leaflet inside the pack.

If you have bleeding that worries you or that will not stop, please seek medical help without delay. If you have concerns about other side effects, you should contact your healthcare team.3

Do not stop taking your medication without talking to your doctor first, because the risk of developing a blood clot could be higher if you stop treatment suddenly.3

1. NHS. Overview. Anticoagulant medicines. May 2018. Available at Last accessed December 2020.

2. Healthline. How to tell if you have a blood clot. March 2019. Available at: Last accessed; December 2020.

3. Stroke Association. Atrial fibrillation (AF) and stroke. May 2019. Available at root/f26_atrial_fibrillation_and_stroke_v4_web.pdf. Last accessed December 2020.

4. NHS. Considerations – anticoagulant medications. May 2018. Available at Last accessed December 2020.

5. Sabzwari SRA et al. Cureus 2018; 10: e2682.

PP-ELI-HKG-0657 JUN 2021