The HSE is asking the public to stay away from emergency services on Wednesday unless absolutely vital.
It has begun outlining details of expected disruption to services during the first of six 24-hour nationwide work stoppages by more than 35,000 nurses.
The action by members of the INMO follows the breakdown of talks at the WRC on Friday.
The HSE says many of their services will be unavailable on the day of the strike - but if you have an appointment or procedure that is cancelled they will contact you directly to reschedule.
The health service has asked the public to stay away from emergency services unless it is absolutely necessary.
Among the services listed as unavailable on the HSE website are planned inpatient surgeries, day case procedures, and all outpatient appointments - including adult, maternity and pediatric.
It says updates will continue to be provided through the website and on social media.
