Data from the UK Health Security Agency shows that the common cold – which can be dangerous for vulnerable people – has also been on the increase in recent weeks.
Surrey and Sussex Healthcare NHS Trust said it was “urgently” trying to get corridor patients into an appropriate setting as quickly as possible.
It added: “Our staff are working hard to keep patients safe, support ambulance services… and admit all those who need our care.”
The trust urged people with non-urgent conditions to use other NHS services, such as 111, their local pharmacy or GP, or nearby treatment centres at Crawley, Caterham Dene, Horsham and East Grinstead.