Some non-urgent surgery is being halted at 17 hospitals across Greater Manchester due to the “rising impact” of Covid-19 and staffing shortages.
Health bosses in the region said about 15% of their workforce were either ill with Covid or isolating.
Greater Manchester Health and Social Care Partnership said it was “a temporary measure” but the “challenges may get worse” in the next fortnight.
A number of hospital trusts elsewhere have declared critical incidents.
The Greater Manchester partnership said cancer care, cardiac and vascular surgery, and transplantation would not be affected.
Diagnostics and outpatient services will also continue wherever possible and patients affected by the changes will be contacted.
Staff absence is the main cause but Covid admissions are also rising sharply, with more than one in five patients in some of the region’s hospitals testing positive.
Outbreaks “in an increasing number of care homes” are also affecting hospital discharges, the partnership said.
“The bed modelling suggests these challenges may get worse, not better, in the next week or two,” it added.
Fiona Noden, chief executive of Bolton NHS Foundation Trust, said the suspension of surgery had been “a very difficult decision” taken to ensure “we can keep people safe”, maintain infection control, deploy staff where they are needed most, and “keep looking after people who need urgent and emergency care”.
She urged people to “come forward for help and treatment in the usual way, using their local emergency department only for serious illnesses or injuries”.
Elsewhere in England, Norfolk and Waveney’s care system has been placed on the highest state of alert.
In the North West, University Hospitals of Morecambe Bay NHS Trust and Blackpool Teaching Hospitals have also declared critical incidents.
Such measures are taken when health bosses are concerned they cannot provide priority services such as treatment for cancer or heart disease.
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