All non-elective surgeries have been cancelled at Cork University Hospital because of overcrowding.
Patients have been informed of the decision, which was made because of pressure on the emergency department.
The HSE said CUH had been exceptionally busy in recent weeks, in particular from January 11-19 when 1,735 patients presented to the emergency department for review and treatment of which 892 patients required inpatient admission.
Staff have also had to deal with an increase in patients presenting with flu-like symptoms and others injured after falls in the recent cold snap.
Apologising for delays in the emergency department, the HSE said the increase in attendance was due to the “large number of very ill medical patients requiring admission and the recent weather conditions which resulted in a large number of patients presenting with injuries sustained as a result of a fall”.
“This decision has been taken in the interest of patient care and with the aim of reducing pressure on the hospital as a whole,” it said.
“Patients affected by this rescheduling have been contacted, the hospital wishes to apologise for any inconvenience caused, and to assure patients that appointments will be rescheduled as soon as possible.”
Additional reporting by Stephen Rogers, the