It is one of a number of NHS trusts in England which have declared critical incidents amid “exceptionally high demands” on emergency departments.
University Hospitals Birmingham NHS Foundation Trust runs Good Hope, Heartlands and Solihull hospitals, and Queen Elizabeth Hospital Birmingham.
Experts said this flu season is the “straw that is breaking the camel’s back” when it comes to urgent care.
Non-urgent patients have been warned they will face long waits in A&E and have been urged to “consider other options”, such as contacting their GP, visiting a pharmacy or calling NHS 111.
Hampshire Hospitals NHS Foundation Trust and University Hospitals Plymouth NHS Trust declared critical incidents on Tuesday morning, followed by University Hospitals Birmingham NHS Foundation Trust this afternoon (Tuesday January 7).
Critical incidents can be declared when health and care services are so busy that special measures are needed to restore normal operations and keep patients safe.
Margaret Garbett, chief nurse at University Hospitals Birmingham NHS Foundation Trust, said its situation is down to “extreme pressures” across services.
“This significant and sustained pressure is due in part to exceptional numbers of patients with flu requiring admission to hospital, this has now reached 311 inpatients and measures including mask-wearing in all departments is also being introduced,” she added.
“Despite expanding capacity in our wards and in our emergency departments, A&E remains overcrowded with extended waits to be seen.”