The head of the HSE says Naas General Hospital is 'back to where it was in April' due to a COVID-19 outbreak.
77 staff at the hospital are off work as they're either a confirmed case or a close contact.
As a result, elective surgeries and outpatient appointments at the hospital have been suspended for two weeks.
A number of other hospitals are also under pressure.
Letterkenny University Hospital has 55 staff unavailable, while there are 161 off between University Hospital Limerick and Ennis Hospital.
HSE chief executive Paul Reid said outbreaks are having a significant impact on staffing.
He explained: "We are losing a lot of staff on shifts, and it's causing significant disruption.
"In one case, we've had to cease all elective care - they are now back where they are in April of just doing urgent care. That's in Naas."
Mr Reid said the hospital is currently just dealing with critical and urgent care.
