Blood clots in a vein and pancreatic cancer

People with pancreatic cancer are at higher risk of a blood clot forming in a vein. You might have heard this called deep vein thrombosis or DVT.

The risk of a blood clot is higher because of your cancer and cancer treatment, though it will not usually affect your treatment.

A blood clot that forms in a vein is known as deep vein thrombosis (DVT) or venous thrombosis.

What is a blood clot?

If you cut yourself, a scab will form over the cut. This is formed by the blood clotting. Platelets (a type of blood cell) and fibrin (a type of protein) in your blood clump together to help the blood to clot. This is normal and stops the bleeding.

Sometimes a blood clot can form in a vein without any bleeding happening, which is not normal. This often happens in the lower leg (calf), upper leg (thigh) or arm. With pancreatic cancer this may also happen in veins near the pancreas such as the splenic vein or portal vein. This is called a deep vein thrombosis (DVT), and it can block the normal flow of blood through the veins.

Part of the clot may break off and travel to the lungs, where it can cause a blockage. This is called a pulmonary embolism (PE), which can be very serious.

A blood clot in a vein is serious and needs to be treated straight away.

Most blood clots can be successfully treated with blood thinning (anticoagulant) medicines.

Common symptoms of a blood clot in a vein

If you get any of these symptoms, tell your doctor or medical team straight away, or go to A&E. But be aware that blood clots do not always cause symptoms.

Symptoms of deep vein thrombosis (DVT) include:

  • pain, swelling or tenderness in one of your arms or legs – often in the lower leg
  • warm skin in the affected area
  • a heavy ache in the affected area
  • your skin may look red or a different colour to normal in the affected area.

Symptoms of pulmonary embolism include:

  • shortness of breath, which can start suddenly or gradually
  • sudden pain in your chest (especially when breathing in)
  • coughing – usually a dry cough but can include coughing up blood
  • extreme tiredness (fatigue)
  • feeling dizzy, lightheaded, or fainting.

Why are people with pancreatic cancer more at risk of getting a blood clot?

There is a higher risk of getting a blood clot if you have cancer. If you have pancreatic cancer the risk is even higher, and people with advanced (metastatic) pancreatic cancer are more at risk.

There are many reasons for this including:

Your risk may also be higher if you:

  • have an inherited condition that makes blood clots more likely, such as Factor V Leiden
  • use hormone replacement therapy (HRT) or a contraceptive pill that contains oestrogen
  • have varicose veins (swollen veins)
  • have had a blood clot before, or a close relative has
  • are over 60
  • are obese, or you smoke.

Can anything help reduce my risk of a blood clot?

Speak to your medical team about your risk of getting a blood clot and whether you can do anything to help reduce it. This might include keeping as active as you can and moving your legs when sitting down. Try to drink plenty of fluids, as you are more likely to get a clot if you are dehydrated.

If you are having surgery and chemotherapy, your medical team may also recommend things to reduce your risk of a blood clot.

What if I go into hospital?

If you are staying in hospital you will move around less, which increases the risk of a blood clot. You should be given information about how to reduce the risk, and your medical team should check for blood clots regularly. You may be given surgical stockings to wear to improve the blood flow in your legs. You will probably also be given medicine to thin the blood, which helps reduce your risk of a clot.

The medical team will get you moving as soon as possible. If you are not able to move around much, there are exercises you can do in bed. These include simple foot exercises, such as bending and straightening your toes. Try to drink enough fluids.

What if I’m having chemotherapy?

If you are having chemotherapy, your oncologist (cancer doctor) should consider whether you need blood thinning medicine to reduce the risk of clots. If you are given this, you will take it for as long as your chemotherapy lasts, or longer if your oncologist thinks you need it.

If you are already taking blood thinning medicine your oncologist will check that it’s suitable while you are having chemotherapy, and may change it.

You should be given information on ways to reduce the risk of a blood clot. Try to move around as much as possible, and drink plenty of fluids. If you have any symptoms that might be a sign of a blood clot, call the 24 hour emergency number you were given when you started chemotherapy. If you can’t get through on the emergency number, go to A&E.

What if I’m having radiotherapy?

If you are having radiotherapy for pancreatic cancer, you will not normally get medicine or surgical stockings to reduce the risk of clots. Radiotherapy treatment doesn’t increase the risk of getting a blood clot.

Read more about things that can reduce your risk of a blood clot. If you have any symptoms that might be a sign of a blood clot, tell your GP or medical team straight away, or go to A&E.

How is a blood clot diagnosed?

If your doctor thinks you have a DVT, you will usually have an ultrasound scan of the affected area. This is called a ‘Doppler’ and looks at the flow of blood through blood vessels.

If your doctor thinks you have a pulmonary embolism, you may have a computed tomography pulmonary angiogram (CTPA). This is a type of X-ray that looks for a blood clot in the blood vessels in the lungs.

How is a blood clot treated?

Blood clots can usually be treated without stopping your cancer treatment. If you get a blood clot you will probably be given blood thinning medicines. You may hear these called anticoagulant medicines.

There are different types of blood thinning medicines that may be used.

  • Direct oral anticoagulants (DOACs) are tablets, usually taken once a day. Examples are rivaroxaban and edoxaban.
  • Low molecular weight heparins (LMWHs) are medicines given once or twice a day as a small injection into the tummy (abdomen). Examples are enoxaparin and dalteparin.

You will have blood thinning medicines for three to six months at first. Your doctor will then review your treatment, to check whether you need to carry on taking it.

There is a risk that you could get a blood clot again after you finish blood thinning treatment. Contact your medical team or go to A&E if you get any of the symptoms.

Side effects of blood thinning drugs

The main side effect of blood thinning medicines is bleeding for longer than usual, for example if you cut yourself or have a nosebleed. This is because it will take longer for a normal clot to form to stop the bleeding. You may also find that you bruise more easily.

If you are having injections, you may get bruises in the injection area.

Ask your medical team about the side effects before you start the treatment.

You should be given an information sheet about your blood thinning medicine so you know what to expect, including how to take the medicine, the side effects and when to get help. You should also be given an anticoagulant medicines alert card that you should always carry with you.

Read our fact sheet about blood clots

You can read about blood clots in our fact sheet: blood clots in a vein and pancreatic cancer.

Download our fact sheet
page 1 of the fact sheet

Questions about blood clots?

If you have any questions about blood clots, speak to your doctor or nurse.

You can also speak to our specialist nurses on our free Support Line.

Speak to our nurses
PCUK Specialist Nurse, Dianne Dobson, taking a Support Line call on the phone

Published August 2022

Review date August 2025