At the RVH on Monday, News NI heard one person with flu was being treated in a unused tea room.
Three others have been in the same area for four days.
Emergency department lead nurse Claire Wilmont said that staff were “treating the most vulnerable elderly sick patients in an intolerable environment”.
“We are dealing with the really elderly, vulnerable and really sick patients at the minute and due to the rising level of flu, we are really struggling to look after people,” Nurse Wilmont said.
She explained that staff were stretched on a daily basis.
“The staff are trying their best, but there are delays and the care at times can be very challenging,” she added.
