The authority says the changes happen every summer and allow for better management of available staff to cover services.
A number of hospital beds will be closed at inpatient units at the Cape Breton Regional Hospital in Sydney, Northside General Hospital in North Sydney and Inverness Consolidated Memorial Hospital.
The authority says operating rooms at New Waterford Consolidated Hospital, Northside General and the Glace Bay Health Care Facility will also close in early July and reopen in early August.
One of four operating rooms at the Cape Breton Regional Hospital will close in early July until late August.
Staffing levels will also affect the intensive care unit in Glace Bay, which will shut down in early July until early September.
Shorter, two-week closures are also planned for the hospital's obstetrics unit and perinatal clinic, as well as the palliative care unit in Sydney and the rehab unit at Harbour View Hospital in Sydney Mines.