There has been much written about how to protect yourself from catching the new coronavirus but far less on what it does to those who catch it. Yet doctors are learning more about the disease every day as cases mount and detailed case reports are starting to appear in medical journals across the world.

They describe a wide spectrum of illness ranging from cases that are so mild the patient does not notice to those where patients decline at pace and die within a week.

The data currently suggest that some 80 per cent of confirmed Covid-19 cases are mild, with 15 per cent severe and five per cent critical.

Over time it is likely that mild cases will grow as a proportion of the total as more asymptomatic cases are picked up through community testing.

Everyone, no matter their age, is susceptible to catching the virus and passing it on to others - although early data suggests the “risk of severe illness, disease and death” increases markedly in people over 60 and in people with underlying conditions.