World Thrombosis Day


About the World Thrombosis Day (WTD) Campaign

What is World Thrombosis Day (WTD)?
WTD is an educational campaign aimed at reducing the significant burden caused by thrombosis. Created and led by the International Society on Thrombosis and Haemostasis (ISTH), WTD is a global collaboration carried out by thousands of local, regional, national and international organizations and advocates. Through community events, lectures, health fairs, scientific meetings, employer presentations, social media and more, WTD raises awareness of thrombosis to the public - people of all ages and nationalities - and healthcare professionals alike.

How can I/my organization get involved?
There are many ways to get involved. As an individual or on behalf of an organization, hospital and institution, you can join the camapign to hold or take part in WTD activities. Join online at Browse our website for information and resources to help you get started. The partner toolkit includes campaign messages, materials and examples of previous WTD activities. You can also order WTD merchandise to promote your event and motivate others involved in the cause.

What is the goal?
The goal of WTD is to alert the world about the importance of reducing death and disability from thrombosis, to Know Thrombosis. WTD encourages participating organizations to raise awareness of thrombosis including the risk factors, signs and symptoms for specific thromboembolic conditions like deep vein thrombosis (DVT), pulmonary embolism (PE), venous thromboembolism (VTE) and stroke caused by atrial fibrillation (AFib). Long term, we seek to reduce the number of undiagnosed cases, disability and death by increasing use of risk assessments and evidence-based prevention and treatment.

What is the primary campaign message?
1 in 4 people worldwide die from conditions caused by thrombosis. Thrombosis is the formation of potentially deadly blood clots in the artery (arterial thrombosis) or vein (venous thrombosis). Once formed, a clot can slow or block normal blood flow and even break loose and travel to an organ. Thrombosis is the often preventable underlying pathology of heart attack, thromboembolic stroke, and venous thromboembolism (VTE), the top three cardiovascular killers.  

Venous thromboebolism (VTE), a form of thrombosis, is a major cause of death and disability and affects people of all ages, genders and ethnicities. Many VTEs (up to 60%) occur during or following a hospital stay, making VTE a leading cause of preventable hospital death. Public awareness of VTE is low and awareness of hospitalization as a risk factor is even lower.

WTD encourages the public to Open Eyes to Thrombosis by learning more about the signs, symptoms and risk factors of thrombosis.

What is the long-term vision?
Our mission supports the World Health Assembly's global target of reducing premature deaths by non-communicable disease by 25 percent by 2025, as well as the World Health Organization’s Thirteenth General Programme of Work 2019–2023, the Montevideo Roadmap 2018-2030 on NCDs and the Political Declaration of UNGA' Third High-level Meeting on NCDs.

When does it take place?
WTD is a year-long campaign that takes place on 13 October, the birth date of Rudolph Virchow, a German physician/pathologist who paved the understanding of thrombosis and the pathogenesis of venous thromboembolism.

Where does it take place?
Professional societies and patient advocacy groups in more than 100 countries around the world conduct awareness-building activities. All WTD partners understand the urgency to raise awareness of thrombosis to curb unnecessary death and encourage others to join them. Thousands of WTD activities take place at universities, public venues, scientific meetings, businesses, hospitals, health clinics, and additional venues that connect the public to this important issue. 

Who founded and leads WTD?
The International Society on Thrombosis and Haemostasis (ISTH) founded and leads WTD with oversight from a dedicated Steering Committee of global medical experts. The ISTH works in close collaboration with a host of national and international organizations from more than 100 countries around world.

Who are the partnering organizations?
More than 2,000 organizations (and counting) are participating in WTD. These groups include societies of vascular medicine, hemostasis and thrombosis, as well as widely recognized international cardiovascular, neurology, hematology and other organizations concerned with the disease burden caused by thrombosis. Among others, our partners include the Centers for Disease Control and Prevention, the National Institutes of Health, the World Heart Federation, NCD Alliance, and the World Stroke Organization.

What are supporters and partners doing to recognize WTD?
We appreciate the incredible diversity of our partners around the world, and we are sensitive to each organization's capacity and resources. Organizations conduct their own public and professional education activities leading up to and beyond WTD. In 2018, more than 10,000 events/activities took place on/around 13 October. 

If you have any questions, contact the WTD campaign at