Cancer and Blood Clot Risk

Blood clotting is an important function of our blood that helps stop bleeding when we are injured. Unfortunately, blood clots can develop in other areas of the body and cause potential complications. Patients with a cancer diagnosis or history of a cancer diagnosis are at an increased risk of developing these potential life-threatening blood clots. It’s important to understand risk factors and potential signs and symptoms of blood clots so that you can notify your care team quickly of these changes. 

What are venous blood clots? 

You may have heard of the term VTE. This is a general term for blood clots that occur in the veins and include deep vein thrombosis (DVT), venous thromboembolism (VTE), and pulmonary embolism. DVT’s often occur in a deep vein like those found in the arms or legs, but can develop in other areas of the body. Pulmonary embolisms are blood clots that develop or travel to your lungs.

Am I at risk for blood clots because of my cancer diagnosis? 

The connection between cancer and increased chances of developing blood clots is not totally understood. Research suggests that many factors can contribute to increased risk of VTE such as-certain chemotherapy drugs, area of the body the tumor is in, stage of disease, and how tumor cells affect normal cells in the bloodstream. 

Are there other risk factors? 

A few of the general risk factors for developing blood clots include: 

  • Diabetes 

  • High blood pressure 

  • Smoking 

  • Dehydration 

  • Lack of exercise or movement 

  • Genetic predisposition (Factor V Leidein, Protein C Deficiency, Protein S Deficiency)  

Are there signs and symptoms to look for? 

Depending on where the clot has developed, symptoms may vary. Also, research has proven that the period of highest risk for developing a blood clot is immediately after a cancer diagnosis and during the first 3-6 months.  DVT’s typically develops in one of the arms and/or legs. Commonly reported symptoms include:  

  • Pain in the arms or legs (usually on one side) 

  • Swelling in the arms or legs (usually on one side) 

  • The area may appear red and feel warm to the touch 

PE’s may cause symptoms of:  

  • Shortness of breath 

  • Chest pain which can be throughout the general chest area or isolated to one specific area 

  • Discomfort in the upper body or back 

  • Pain in the jaw or neck areas. 

Good to know: If you notice any of these symptoms, notify your care team right away as this can be a medical emergency. 

Are there things I can do at home to help reduce my risk?  

While you can’t entirely prevent the development of a blood clot, there are steps you can take that can help decrease the risk. Some of the actions you can take include:  

  • Maintain a healthy diet by avoiding foods high in sugar and saturated fats. When possible, choose whole fresh foods over processed foods.  

  • If you smoke, consider smoking cessation. The Iris mental health team is available to support you through this process. Click here to book an appointment. 

  • Stay well hydrated by drinking plenty of water.  

  • Be physically active (make sure to confirm with your physician the level of activity you can engage in). Walking is a great way to maintain healthy blood flow.  

  • If you have limited mobility, you can do simple pedal exercises by raising your heels and pressing the balls of your feet into the floor, then alternate to pressing your heels to the floor and lifting the balls of your feet to promote blood flow in your legs.  


​​Emanuele Previtali, P. B. (2011). Risk factors for venous and arterial thrombosis. Blood Transfusion, 120-138. doi:10.2450/2010.0066-10 

​Norbaini Binti Abdol Razak, G. J. (2018). Cancer-Associated Thrombosis: An Overview of Mechanisms, Risk Factors, and Treatment. Cancers. doi: 

​Tzu-Fei Wang MD, A. L. (2018). Managing thrombosis in cancer patients. Research and Practice in Thrombosis and Haemostasis, 429-438. doi: 10.1002/rth2.12102 

​Wang, H., Xu, X., Pu, C., & Li, L. (2019). Clinical characteristics and prognosis of cancer patients with venous thromboembolism. Journal of Cancer Research and Therapeutics, 344-349. doi:10.4103/jcrt.JCRT_121_18