Patients attending Letterkenny University Hospital have been warned they face lengthy delays.
The increased waiting times come as the hospital continues to battle the ransomware attack on the HSE IT systems.
A spokesperson said the issue continues to have a considerable impact on hospital services at Letterkenny University Hospital.
“Patients attending the Emergency Department are facing extremely long delays as the radiology, laboratory and pharmacy systems are not up and running.
“Essential services like blood tests and diagnostic services are taking much longer to operate than usual, using manual processes which is significantly increasing turnaround times for patients.
“Patients needing urgent care will be prioritised. We ask patients to contact their GP or GP Out Of Hours Service in the first instance if their health problem is not urgent.
“Where possible patients should bring their existing patient number or hospital number with them when they come to the hospital or any letter that they have received from the hospital as this will contain information which will make it easier to find existing medical records.
“We apologise for the long waiting times that patients are currently facing.”