The HSE has said the Midland Regional Hospital in Portlaoise is experiencing increasing numbers of people requiring admission.
It is asking patients with non-emergency conditions to seek assistance from other parts of the health service such as their local Pharmacist, GP, GP out-of-hours service, or a local injury unit.
It said that patients who are presenting at the emergency department with non-urgent conditions are experiencing very long waiting times to be seen.
It has stressed, however, that any patient who needs emergency hospital care will be seen and such patients should not delay attending the emergency department.
The hospital said it continues to monitor the situation closely and will provide further updates as necessary.