Long delays have been reported at the Emergency Department at University Hospital Limerick, including long waits for access to beds.
In a statement, the hospital said the delays are a result of high volumes of patients.
The hospital has said "every effort is being made ... to reduce wait times".
Daily attendances at the Emergency Department average 240 last month, an increase of 22% compared to 2019.
Members of the public have been asked to "consider all their care options" before attending the Emergency Department.
The hospital said that injury units - suitable for the treatment of broken bones, dislocations, sprains strains, wounds, scalds and minor burns - are open in Ennis, Co Clare and Nenagh, Co Tipperary from 8am to 8pm.
People with less serious injuries are asked to contact their GP or out-of-hours GP service.