Patient information from BMJ

DVT and long-distance travel

Last published:Aug 05, 2025

If you have deep vein thrombosis (DVT), it means a blood clot has formed in a vein deep inside your body. It is most likely to happen in your leg. DVT can be dangerous if parts of the clot break off and travel to your lungs. This patient information is about ways of preventing DVT when traveling.

Am I more likely to get DVT when traveling?

DVT is more likely if you can't or don't move about for long periods. This may be why people have a greater chance of DVT if they go on a long journey, such as a long flight. However, the risk of DVT while traveling is still low for most people. It is more likely to happen if you have other things that already give you a higher risk of DVT, or have had a blood clot before.

Things that may increase your chance of DVT include:

• being older

• being very overweight (obese)

• having had a recent surgery or injury

• being bedridden for 3 days or more

• being in hospital within the last 2 months

• having a blood clotting disorder

• being pregnant, or recently giving birth

• taking hormone therapy, and

• having cancer.

The length of your journey, or the length of the time you are likely to be seated while traveling, is also important. For example, flights more than about 4 hours long are considered more likely to increase your risk of DVT. But it is not only flights that can cause a problem. Sitting still during longer journeys in other types of transport, such as a car or train, may increase your risk of DVT too. 

How will I know if I get DVT?

It is important to know what to look out for, so that if you get any symptoms of DVT you can get medical help quickly. The main symptoms are swelling or pain in the calf or thigh of one leg, or both swelling and pain. Sometimes people notice the painful area in their leg feeling hot. Sometimes the skin over the painful area may turn red or purplish. If a clot has travelled to your lungs, you may get chest pain or shortness of breath.

If you get DVT because of sitting still on a long-distance journey, you may not notice any pain or swelling right after the trip. It can take hours or even days or weeks for you to get any symptoms.

How can I reduce my chances of getting DVT while traveling?

DVT is more likely in people who have had a blood clot before. This could have been a clot in your legs, or somewhere else in your body. If you have had a blood clot, you should avoid long-distance flights for at least 2 weeks after your diagnosis.

If you have had a blood clot more than 2 weeks ago, or are at increased risk of DVT for other reasons but are able to travel, your doctor may recommend some things you can do to help reduce the chance of a clot forming. For example, they may recommend wearing special elastic stockings called compression stockings.

These stockings help to keep the blood flowing smoothly through the veins in your legs. This makes it less likely that a clot will form. Your pharmacist can measure you to ensure you buy the right size of stockings. But the stockings are not suitable for everyone, so ask your doctor about them first.

Whether or not you are at high risk, you should try and keep active whilst on long-distance travel. Here are some things you can try:

• Avoid sitting still for long periods. For example, you could get up and take short walks around the cabin of your aeroplane or train compartment. If you are in a car or bus, take a short walk whenever you stop for a break. If you are driving, make sure you schedule regular breaks.

• Try to exercise your legs. Ask your doctor or nurse about exercises you could do while traveling.

• Stay hydrated. Drink plenty of water and other fluids.

What else can I do?

If you are worried about getting a blood clot, speak to your doctor. They will be able to talk to you about your personal risk. They will also be able to assess whether any specific treatments could help lower your risk.

To try and reduce your risk of getting DVT in the long term, you can also:

• Stop smoking, if you smoke.

• Try to keep to a healthy weight.

• Stay active.