13th October 2020

Today is World Thrombosis Day. It’s a global event that seeks to improve awareness of the causes, risk factors, and signs and symptoms of thrombosis: blood clots blocking your blood vessels. Thanks to COVID-19, the serious nature of blood clots has been increasingly discussed in the media and medical journals in 2020 because of the high rates of thrombosis seen in hospitalized COVID-19 patients.  

Back in May physicians at the Royal Brompton Hospital established a “clear link” between COVID-19 and blood clotting.1 Rates of thrombotic complications such as deep vein thrombosis (DVT) and pulmonary embolism (PE) are particularly high among critically ill COVID-19 patients.2 The main reasons appear to be immobility of patients in intensive care and the body’s immune response to the virus and the inflammation it causes, which increases the liver’s production of clotting factors.3 

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In the NHS, patients who are being hospitalized with a SARS-CoV-2 infection will be reviewed and given anticoagulation therapy where this is necessary. However, it is not yet entirely clear what the recommended dose of anticoagulants should be for this specific patient group. Doctors need to weigh the benefits of blood thinning and preventing clots from forming with the risk of bleeding. A number of clinical trials around the world are therefore investigating this question,4 among them the REMAP-CAP trial5 in the UK.

If you want to learn more about thrombosis, there are thousands of educational (virtual) events taking place today around the world to raise awareness of the health impact associated with blood clots. To find out more visit https://www.worldthrombosisday.org/. 


1. British Society for Haematology: https://b-s-h.org.uk/about-us/news/clear-link-between-covid-19-and-blood-clotting-uk-research-team/ (accessed October 2020).

2. Science Daily: https://www.sciencedaily.com/releases/2020/10/201001113553.htm (accessed October 2020). 

3. BMJ May 2020: https://www.bmj.com/content/369/bmj.m2058 (accessed October 2020). 

4. Pharmaceutical Journal October 2020: https://www.pharmaceutical-journal.com/news-and-analysis/features/everything-you-need-to-know-about-the-covid-19-therapy-trials/20208126.article?firstPass=false (accessed October 2020).

5. REMAP-CAP: https://www.remapcap.org/ (accessed October 2020).