Norfolk and Waveney CCG area placed on highest alert
A county's healthcare system was moved to the highest alert level after one of its hospitals became "extremely pressured".
Norfolk and Waveney went to Opel 4 over fears patient care could be compromised.
Norfolk and Norwich University Hospital staff were asked to discharge patients "safely and quickly".
Local health leaders are calling on the public to think twice before attending A&E.
The alert was issued on Wednesday afternoon, but the hospital has since moved back to Operational Pressures Escalation Level (Opel) 3.
Opel 4 - also known as black alert - is when demand within a local health and social care system escalates to a level in which organisations are unable to deliver comprehensive care.
NHS guidance says it also means there is increased potential for patient care and safety to be compromised.
Pressure 'continuing to mount'
In an email from the hospital's director of operations, Chris Cobb, staff were told "immediate action" was required in order to take in patients from the community who required an emergency response.
It said: "This will require all of us to work together throughout the rest of the day to get the hospital in to a better shape and we will not be able to stand down until we can assure ourselves we have enough capacity for our emergency patients."
Norfolk and Waveney Clinical Commissioning Group (CCG) said pressure was "continuing to mount on local NHS services" and requested the public not to turn up at A&E but to dial NHS 111 first, or visit a local pharmacy or contact their GP.
CCG chairman Dr Anoop Dhesi said: "All local health services continue to be very busy and staff in every area are continuing to work incredibly hard to make sure that everyone receives the treatment they need as quickly as possible.
"Please think twice about attending A&E unless it is an absolute emergency."
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