Thrombosis, or blood clots that block veins or arteries, is one of the complications of COVID-19. Research has found that the incidence of arterial and venous thrombosis increases significantly in COVID-19 patients.
In addition, some people have rare side effects such as thrombosis with thrombocytopenia syndrome after they get vaccinated; antibodies produced by the vaccine activate platelets, resulting in low platelet count and blood clots.




