Up to 30% of patients who are seriously ill with coronavirus are developing dangerous blood clots, according to medical experts.
They say the clots, also known as thrombosis, could be contributing to the number of people dying.
Severe inflammation in the lungs – a natural response of the body to the virus – is behind their formation.
Patients worldwide are being affected by many medical complications of the virus, some of which can be fatal.
The virus has also increased cases of deep vein thrombosis – blood clots usually found in the leg – which can be life-threatening when fragments break off and move up the body into the lungs, blocking blood vessels.