Cookies on the Bupa website

We use cookies to help us understand ease of use and relevance of content. This ensures that we can give you the best experience on our website. If you continue, we'll assume that you are happy to receive cookies for this purpose. Find out more about cookies



Deep vein thrombosis (DVT)

Deep vein thrombosis (DVT) is a condition in which a blood clot forms in one of your deep veins. This is usually in one of the large veins in your leg. You can also get DVT in your pelvis or your abdomen.

DVT causes pain and swelling. If the blood clot moves and travels to your lungs, it can lead to a pulmonary embolism, which can be life-threatening. Every year in the UK, about one in 1,000 people get a DVT.

How deep vein thrombosis (DVT) forms
Deep vein thrombosis (DVT) happens when a blood clot forms in a deep vein

Symptoms of deep vein thrombosis

Most people with DVT won’t have any symptoms. If you do have symptoms, they can vary from mild to severe and can affect any part of either leg.

If you have a blood clot that is large and mostly or totally blocks your vein, you may have some symptoms. These include:

  • a swollen leg
  • pain and tenderness along the line where your vein is
  • warm skin that looks red

These can often be symptoms of other conditions too. In fact, only about one in three people with a swollen and painful leg will have DVT. If you have any of these symptoms, contact your GP as soon as possible.

Diagnosis of deep vein thrombosis

Your GP will ask about your symptoms and medical history, and examine you. They’ll make an assessment of how likely you are to have a DVT, based on all your symptoms and risk factors. If your GP thinks a DVT is likely, they’ll refer you for some tests to confirm the diagnosis. These may include the following.

  • A blood test called a D-dimer. This measures a substance called fibrin, which develops in your body when a blood clot breaks down. The test is usually used to rule out DVT as the cause of your symptoms. D-dimer tests may be positive or raised if you have other health conditions such as cancer, or after an operation.
  • A leg vein ultrasound. This uses sound waves to look at your blood as it flows through the blood vessels in your leg.

Treatment of deep vein thrombosis

Treatment for DVT aims to stop the blood clot in your vein progressing and getting worse. It also aims to reduce your likelihood of developing complications from DVT, and your risk of getting another DVT.


The main treatment for DVT is a type of medicine called an anticoagulant. Anticoagulants prevent blood clots forming or stop blood clots getting bigger.

If your doctor suspects you have a DVT, you’ll usually start treatment with an anticoagulant before your diagnosis is even confirmed. Which type of anticoagulant your doctor recommends will depend on your general health and what caused your DVT, as well as local guidelines and your doctor’s own experience. You can usually receive treatment through your GP or as an outpatient at your local hospital. But you may need to be admitted to hospital for treatment if you have any complications, or if you’re at increased risk of bleeding.

The two main types of anticoagulant used for DVT are:

  • novel anticoagulants (NOACs)
  • heparin (injections) and warfarin

Your doctor may recommend trying an NOAC first. NOACs include rivaroxaban, dabigatran, apixaban and edoxaban. These medicines have the advantage that you don’t need heparin injections with them, and you don’t need to be monitored as closely as with older anticoagulants. If you have certain health conditions, an increased risk of bleeding or are pregnant, you may not be able to have NOACs.

If you’re unable to have treatment with an NOAC for any reason, you’ll usually be offered treatment with low-molecular weight heparin (LMWH) and warfarin. LMWH is given as an injection under your skin, while warfarin is taken as tablets. You’ll need to have both treatments to begin with, because it takes a few days for the warfarin to start to work. You’ll be able to stop the LMWH after around 5 days. But you’ll probably need to continue taking the warfarin tablets for three to six months, sometimes longer.

If you have kidney failure or you’re at high risk of bleeding, you may need treatment with another type of heparin – called unfractionated heparin. You’ll need to go into hospital to have this, where doctors will be able to monitor you.

You’ll need to have regular blood tests if you’re taking warfarin, to make sure your blood is clotting properly. This is called an INR test. You won’t need to be monitored in this way if you’re taking an NOAC.

If you’re taking an anticoagulant, your nurse or doctor should give you an alert card, which you should always carry with you. If you’re taking warfarin, you should also be given an anticoagulant information booklet.

If your symptoms get worse when you begin taking anticoagulants or if you develop another DVT, your doctor may try switching you to an alternative treatment.

Inferior vena cava filters

Most people with DVT can have treatment with anticoagulants. But if you can’t for any reason, your doctor may suggest you try treatment with a device called an inferior vena cava (IVC) filter. An IVC filter is a small metal device placed inside a vein to trap any clots before they can travel to your heart and lungs. You may also have one if you have recurrent DVT (it keeps coming back).

Ongoing treatment

Your doctor is likely to advise you to try to start walking as soon as possible after having a DVT. It’s safe to get up and about (it won’t cause the clot to move) and it can help to ease your symptoms.

Your doctor may suggest you wear a compression stocking on the affected leg for up to two years afterwards. These are tight stockings that help to pump your blood through your legs. They can help to reduce any ongoing symptoms you have, and they’re thought to reduce your risk of developing post-thrombotic syndrome (see Complications for more information). The stockings come in different sizes. You should have them replaced every three to six months and have your leg measured each time you get new stockings. Compression stockings aren’t advised for everyone who has had a DVT.

Depending on your medical history and why you developed a DVT, your doctor may recommend you continue taking anticoagulant medicines for the long term. This is to prevent any more blood clots developing.

Bupa Travel Insurance

We offer adaptable cover for a range of holidays including family getaways, short breaks, business trips and more.

Causes of deep vein thrombosis

For as many as half of all people who get a DVT, there is no specific cause. But developing DVT while you’re in hospital, or in the three months after you leave hospital, is common.

There are certain things that are known to be associated with developing DVT. These include:

  • being inactive for long periods of time; for example, if you’re recovering after a big operation or are sitting still during a long journey
  • having blood that clots more easily; for instance, if you’re pregnant, have certain conditions that affect your blood clotting, or you’re taking the contraceptive pill
  • having cancer
  • if your blood vessels have been damaged from an injury or operation

You’re also at greater risk of developing a DVT if:

  • you’ve had DVT before
  • you're over 60
  • you’re a smoker
  • you’ve very overweight (obese)
  • you’re dehydrated (not getting enough fluid)
  • you have a severe infection

Travel risks

If you travel long distances and spend hours sitting down, then you could be more likely to develop deep vein thrombosis.

Any kind of long distance travel (plane, car, coach or train) increases your risk of DVT by about three times, but the risk is still a small one. For example, for flights that last 16 hours or more, there will be one person who develops DVT or pulmonary embolism every 1200 flights. The longer the journey, the greater your chances of getting a blood clot.

Complications of deep vein thrombosis

Most of the time, deep vein thrombosis (DVT) doesn’t cause any further problems. However, possible complications of DVT can include the following.

Pulmonary embolism

A pulmonary embolism happens when a blood vessel in your lungs becomes blocked. A piece of the blood clot in your leg can break off and travel through your body in your bloodstream until it gets to your lungs, where it gets stuck. If blood isn’t reaching your lungs properly, it can be very serious. Getting treatment quickly can be life-saving.

Post-thrombotic syndrome

This is when you have ongoing symptoms after a DVT, such as a painful and swollen leg and red, dry skin. It can happen if the damage caused by DVT increases the pressure in your vein. If the condition becomes severe, you could develop an ulcer on your leg and this can be difficult to heal. Wearing compression stockings may help to prevent post-thrombotic syndrome.

Prevention of deep vein thrombosis

If you're in hospital for a big operation or because of illness, you may be more likely to develop deep vein thrombosis or pulmonary embolism. When you’re in hospital, your nurse or doctor will measure your risk of developing a blood clot. You may be asked to do the following to reduce your risk.

  • Drink plenty of fluids. If you can’t drink, you’ll be given fluids through a drip.
  • Get up and start moving about as soon as you can after an operation or illness.
  • Wear compression stockings to help your circulation.
  • Have an injection of an anti-clotting medicine such as enoxaparin or tinzaparin or daltaparin as well as or instead of wearing compression stockings.
  • Use an intermittent pneumatic compression device. This is an inflatable cuff wrapped around your leg or foot and an electrical pump that inflates it, squeezing your deep veins.

You can also prevent blood clots from developing when you’re sitting down a lot during a long journey by doing the following.

  • Get up and walk around whenever you can.
  • Do leg exercises in your seat, for example, bend and straighten your knees, feet and toes every half hour.
  • Drink enough fluid so you don’t become dehydrated.
  • Drink non-alcoholic drinks and avoid caffeine.

FAQ: Are there risks to treating DVT with anticoagulants?

Anticoagulant medicines stop blood clotting. There are several different ones, including warfarin and newer medicines such as apixaban and dabigatran. Because they affect the way your blood clots, the main side-effect is bleeding.

If you’re taking warfarin, you’ll need to have regular blood tests to make sure your blood is clotting properly. This blood test is called an INR test. There are several things that can affect how well warfarin works – including other medicines you may be taking, if you lose or gain weight or if you’re ill. Having the INR test can help your doctor to make sure you’re getting the right amount of medicine and adjust it if necessary. You won’t need INR tests if you’re taking the newer anticoagulants (NOACs), as you won’t need to change the amount you’re taking.

If you’re taking warfarin, your nurse or doctor should also give you an anticoagulant information booklet and an alert card, which you should always carry with you. The card lets other health professionals know that you’re taking warfarin in case of an emergency or before you have any other treatment.

You can lower the likelihood of any bleeding as a side-effect by:

  • taking the medicines at the same time every day
  • telling your doctor about any bruising straightaway
  • telling any doctor or your dentist that you take an anticoagulant before you start any treatment
  • using paracetamol for pain relief instead of aspirin or non-steroidal anti-inflammatory drugs

FAQ: I've had deep vein thrombosis – could I get it again?

About one in every three people who develop DVT that seems to have no definite cause, will have another one within five years. If you developed DVT after an injury or operation, then your chances of having another one are less – about one in every seven people.

If there is a high chance that you may develop another DVT, your doctor will probably ask you to keep taking anticoagulant medicines for the long term. This could be for years. Your doctor will do regular blood tests to check how your blood is clotting, and may change your treatment depending on the results.


  • Bupa Travel Insurance

    We offer adaptable cover for a range of holidays including family getaways, short breaks, business trips and more.

  • Other helpful websites Other helpful websites

    Further information


    • Deep vein thrombosis. BMJ Best Practice., last updated September 2016
    • Deep vein thrombosis. NICE Clinical Knowledge Summaries., last revised April 2013
    • Superficial thrombophlebitis. NICE Clinical Knowledge Summaries., last revised July 2015
    • Deep venous thrombosis. Medscape., updated March 2016
    • Deep vein thrombosis. PatientPlus., last checked July 2015
    • Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. National Institute for Health and Care Excellence (NICE), 2015.
    • Anticoagulants. NICE British National Formulary., reviewed April 2017
    • Anticoagulants, including non-vitamin K antagonist oral anticoagulants (NOACs). National Institute for Health and Care Excellence (NICE), 2017.
    • Coumarins and phenindione. NICE British National Formulary., reviewed April 2017
    • Percutaneous Transcatheter Treatment of Deep Venous Thrombosis. Medscape., updated December 2015
    • Clarke MJ, Broderick C, Hopewell S, et al. Compression stockings for preventing deep vein thrombosis in airline passengers. Cochrane Database of Systematic Reviews 2016, Issue 9. DOI:10.1002/14651858.CD004002.pub3
    • DVT prevention for travellers. NICE Clinical Knowledge Summaries., last revised March 2013
    • Pulmonary embolism. BMJ Best Practice., last updated September 2016
    • Pulmonary embolism. Medscape., updated April 2017
    • Pulmonary embolism. PatientPlus., last checked September 2014
    • Chronic venous insufficiency and postphlebitic syndrome. The MSD Manuals., last full review/revision July 2016
    • Venous thromboembolism: reducing the risk for patients in hospital. National Institute for Health and Care Excellence (NICE), 2015.
    • Zhao JM, He ML, Xiao ZM, et al. Different types of intermittent pneumatic compression devices for preventing venous thromboembolism in patients after total hip replacement. Cochrane Database of Systematic Reviews 2014, Issue 12. DOI: 10.1002/14651858.CD009543.pub3
    • Prevention of venous thromboembolism. PatientPlus., last checked June 2014
    • Oral anticoagulants. PatientPlus., last checked June 2015
    • Oral anticoagulant therapy. The National Patient Safety Agency., published 2008
    • Kearon C, Akl EA, Ornelas J, et al. Antithrombotic Therapy for VTE Disease: CHEST Guideline and Expert Panel Report. Chest 2016; 149(2):315–52. 
  • Has our information helped you? Tell us what you think about this page

    We’d love to know what you think about what you’ve just been reading and looking at – we’ll use it to improve our information. If you’d like to give us some feedback, our short form below will take just a few minutes to complete. And if there's a question you want to ask that hasn't been answered here, please submit it to us. Although we can't respond to specific questions directly, we’ll aim to include the answer to it when we next review this topic.

    Let us know what you think using our short feedback form
  • Related information Related information

  • Author information Author information

    Reviewed by Pippa Coulter, Specialist Health Editor, Health Content Team, September 2017
    Expert reviewer, Dr Shankara Paneesha, Consultant Haematologist
    Next review due September 2020

About our health information

At Bupa we produce a wealth of free health information for you and your family. We believe that trustworthy information is essential in helping you make better decisions about your health and care. Here are just a few of the ways in which our core editorial principles have been recognised.

  • Information Standard

    We are certified by the Information Standard. This quality mark identifies reliable, trustworthy producers and sources of health information.

    Information standard logo
  • HONcode

    This site complies with the HONcode standard for trustworthy health information:
    verify here.

    This website is certified by Health On the Net Foundation. Click to verify.

What our readers say about us

But don't just take our word for it; here's some feedback from our readers.

Simple and easy to use website - not alarming, just helpful.

It’s informative but not too detailed. I like that it’s factual and realistic about the conditions and the procedures involved. It’s also easy to navigate to areas that you specifically want without having to read all the information.

Good information, easy to find, trustworthy.

Meet the team

Nick Ridgman

Nick Ridgman
Head of Health Content

  • Dylan Merkett – Lead Editor
  • Graham Pembrey - Lead Editor
  • Laura Blanks – Specialist Editor, Quality
  • Michelle Harrison – Specialist Editor, Insights
  • Natalie Heaton – Specialist Editor, User Experience
  • Fay Jeffery – Web Editor
  • Marcella McEvoy – Specialist Editor, Content Portfolio
  • Alice Rossiter – Specialist Editor (on Maternity Leave)

Our core principles

All our health content is produced in line with our core editorial principles – readable, reliable, relevant – which are represented by our diagram.

An image showing or editorial principals

                  Click to open full-size image

The ‘3Rs’ encompass everything we believe good health information should be. From tweets to in-depth reports, videos to quizzes, every piece of content we produce has these as its foundation.


In a nutshell, our information is jargon-free, concise and accessible. We know our audience and we meet their health information needs, helping them to take the next step in their health and wellbeing journey.


We use the best quality and most up-to-date evidence to produce our information. Our process is transparent and validated by experts – both our users and medical specialists.


We know that our users want the right information at the right time, in the way that suits them. So we review our content at least every three years to keep it fresh. And we’re embracing new technology and social media so they can get it whenever and wherever they choose.

Our accreditation

Here are just a few of the ways in which the quality of our information has been recognised.

  • The Information Standard certification scheme

    You will see the Information Standard quality mark on our content. This is a certification programme, supported by NHS England, that was developed to ensure that public-facing health and care information is created to a set of best practice principles.

    It uses only recognised evidence sources and presents the information in a clear and balanced way. The Information Standard quality mark is a quick and easy way for you to identify reliable and trustworthy producers and sources of information.

    Certified by the Information Standard as a quality provider of health and social care information. Bupa shall hold responsibility for the accuracy of the information they publish and neither the Scheme Operator nor the Scheme Owner shall have any responsibility whatsoever for costs, losses or direct or indirect damages or costs arising from inaccuracy of information or omissions in information published on the website on behalf of Bupa.

  • British Medical Association (BMA) patient information awards

    We have received a number of BMA awards for different assets over the years. Most recently, in 2013, we received a 'commended' award for our online shared decision making hub.

Contact us

If you have any feedback on our health information, we would love to hear from you. Please contact us via email: Or you can write to us:

Health Content Team
Battle Bridge House
300 Grays Inn Road

Find out more Close

Legal disclaimer

This information was published by Bupa's Health Content Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition.

The information contained on this page and in any third party websites referred to on this page is not intended nor implied to be a substitute for professional medical advice nor is it intended to be for medical diagnosis or treatment. Third party websites are not owned or controlled by Bupa and any individual may be able to access and post messages on them. Bupa is not responsible for the content or availability of these third party websites. We do not accept advertising on this page.

For more details on how we produce our content and its sources, visit the 'About our health information' section.

ˆ We may record or monitor our calls.