Hospitals have begun cancelling thousands of medical appointments, planned for Thursday, as tensions between nurses and the government deepen.
Up to 50,000 outpatient appointments and planned procedures nationally have not gone ahead today, with 37,000 INMO members picketing 240 hospitals and HSE facilities.
In this region, pickets have been placed on Mayo, Roscommon, Sligo and Galway University Hospitals as well as Merlin Park and Portiuncla Hospitals in Co Galway as well as the injury unit at Roscommon Hospital.
A number of primary care centres and nurse-led day centres are also closed.
Another day of strike action on pay and staff shortages is planned for Thursday, leading to some hospitals texting patients to reschedule.
Over 500 nurses and midwives are involved in today's protest outside Mayo University Hospital in Castlebar.
Despite poor weather conditions, nurses turned out in big numbers to call for increased pay, and safer staffing levels on wards.