There are now at least 65 million people worldwide struggling with symptoms months or years after first falling ill with COVID-19. 

Doctors and scientists don't fully understand this multi-system condition but a new wave of research is underway.

Professor Resia Pretorius and Professor Douglas Kell were the first to discover unusual microclots in the blood of people suffering from Long COVID. 

The microclots are thought to cause symptoms by impeding blood and oxygen flow to the body's organs and tissues.

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RAZOR's Emma Keeling travels to Germany to meet Dr. Beata Jaeger and learn more about an experimental treatment given to Long COVID patients to clear the blood of microclots.

Back in the UK, Keeling meets Dr. Asad Khan, whose whole life has been turned upside down by the condition and is now involved in Long COVID research. 

With millions around the world suffering, more research is urgently needed to better understand this dangerous post viral syndrome.