The Irish Nurses and Midwives Organisation has said 614 patients are waiting for admission to a hospital bed.
The hospital worst affected by overcrowding today is University Hospital Limerick with 74 patients waiting.
There are 49 patients waiting admission to a hospital bed at University Hospital Galway and 42 at Tallaght University Hospital.
The INO said 433 patients are waiting in emergency departments, while 181 are in wards or elsewhere in hospitals.
The INMO counts the number of patients who have been admitted to hospital, but are waiting for a bed.