People in Dublin are being warned that the emergency department at the Mater Hospital is 'very busy'.
Hospital management today says that 'a lot of seriously ill patients' have been admitted recently, with many still waiting for a bed.
They're now asking people to 'think about all their care and treatment' options before travelling to the hospital.
In a statement, a Mater spokesperson said: "We apologise for the distress or inconvenience caused to patients or their loved ones who are experiencing long wait times.
"We are committed to treating everyone who presents at our ED, but we do so strictly in order of medical priority."
The statement adds: "We would ask that people keep our ED services for the patients who need them most. For example, many patients with limb injuries can go to an Injury unit and others with a less serious illness can be treated by their GP or referred by their GP to an Assessment Unit the following day.
"However, if you are seriously injured or ill the ED will assess and treat you as a priority."
The statement adds that the Mater has its own rapid injury clinic in Smithfield in Dublin, where emergency nurses and doctors are on hand to deal with minor injuries.