Thrombosis is a dangerous disease and may cause the blood to clot in the veins of legs, arms or groin blocking the flow of blood and transfer of blood to other organs.

13 October was recognised as the World Thrombosis Day for the first time in the year 2014 by the International Society on Thrombosis and Haemostasis after requests from member countries to dedicate a day for the awareness of thrombosis.

This day is celebrated to educate people to reduce the danger of thromboembolic stroke and prevent deaths due to thrombosis. One of the main objectives of the day is to highlight threat and resulting factors of thrombosis that contribute to the mortality rate.

The theme for world thrombosis day 2021 is 'eyes open to thrombosis'. This theme emphasises the need to be alert and recognise the early warning signs of thrombosis before they become worse.