Minister for Health Simon Harris has said he expects a surge in patients this winter at emergency departments.
There were 526 patients on trolleys in emergency departments or on wards waiting for admission to a bed today, according to the Irish Nurses and Midwives Organisation.
The Wicklow TD predicted that it would be a challenging winter.
Mr Harris said dealing with the overcrowding pressures would require "huge operational grip" and that managers and doctors would have to do all that they can to assist.
He also said that the public also need to also accept this was a very busy time of year.
Mr Harris said that so far this winter, there have been about 2,000 fewer patients on trolleys compared with this time last winter.
But he warned that if there was a flu outbreak that would have an impact.
He said that extra home care packages were in place and more beds were being opened.
Survey shows need for improvements
Meanwhile, the results of a new national hospital patient survey have found that 49% of inpatients could not always find a member of staff to talk to about their worries or fears.
Also 36% of patients said they were not involved as much as they would have liked to have been in decisions about their care.
Only 30% of patients said they were admitted to a ward within the target waiting time of six hours.
Most patients, 54%, rated their experience of admission to hospital as very good.
But the findings show that a large number had negative experiences during their time in hospital.
In the first National Patient Experience Survey conducted last May, 13,700 patients who had been discharged from a public hospital responded out of 27,000 invited - a response rate of 51%.
It found that 56% rated their experience of care on the ward as very good.
The results highlight the need for better communication with patients regarding the side effects of medication, the danger signals to watch out for after discharge and how patients should care for themselves at home.
Just 39% of patients rated their experience of discharge or transfer as very good.
The survey involved 40 hospitals and each will now prepare individual quality improvement plans.
It was conducted involving the Health Information and Quality Authority, the HSE and the Department of Health.
The survey was developed with the involvement of Patient Focus.