The flu is not the main cause of the trolley crisis, according to the Irish Nurses and Midwives Organisation.
The INMO says underlying capacity issues in our hospitals are the reason why hundreds of people are having to wait for beds.
The HSE will give a briefing later on the current impact of the flu outbreak, and the uptake of the flu vaccine.
Dave Hughes from the INMO says frontline staff, like nurses, are overworked and under resourced.
He said: "It's constant pressure, it's a situation where you are trying to cope with many more people than the departments are able to cope with.
"They are trying to provide care in the most extreme of circumstances, so it's a very difficult role that they have."