The Full Capacity Protocol has been implemented at Letterkenny University Hospital.
The Saolta Hospital Group says the Emergency Department at the hospital is extremely busy following the admission of a significant number of ill patients recently, many of whom remain in the ED awaiting a bed.
The hospital has apologised for any distress or inconvenience caused to patients or their loved ones due to long waiting times.
People are being asked to only attend the ED in the case of real emergencies and to contact their GP or GP Out-of-Hours service in the first instance.
According to the INMO, there were 27 people awaiting in-patient beds at Letterkenny University Hospital this morning, 10 of them on Emergency Department trolleys, up 11 on yesterday's figure.