Four hospital trusts in southeast England have declared critical incidents due to "significant and sustained pressures" on services after a "surge" in complex A&E admissions.
NHS Surrey Heartlands said the situation is being "exacerbated by increases in flu and norovirus cases and an increase in staff sickness".
The recent cold snap has also impacted more frail patients who needed to be admitted to hospital, it said.
The critical incidents in Surrey affect three trusts - Royal Surrey NHS Foundation Trust, Epsom and St Helier University Hospitals NHS Trust, and Surrey and Sussex Healthcare NHS Trust.
East Kent Hospitals University NHS Foundation Trust has also declared a critical incident due to "sustained pressures" at the Queen Elizabeth The Queen Mother Hospital in Margate.
It said its hospitals were experiencing "exceptionally high demand, driven by a continued high admission rate and a large number of patients with winter illnesses and respiratory viruses".
The trust added that "beds across our hospitals are currently full and attendance at our emergency departments is extremely high, meaning there is very limited capacity to admit further patients who need acute care".
NHS Surrey Heartlands said the decision to declare critical incidents reflects "a level of NHS escalation that enables trusts to focus on critical services".
It said it was the result of a surge in complex attendances to A&E departments and ongoing challenges in discharging patients who are well enough to leave hospital.
Other critical incidents have also been declared in recent days in Birmingham, Staffordshire and two areas of Wales.
On Saturday, Aneurin Bevan University Health Board in south east Wales said it was suffering "sustained pressure" and on Monday confirmed it was seeing "a significant increase of norovirus cases across Gwent".
Meanwhile, on Thursday, University Hospitals of North Midlands NHS Trust in Staffordshire, University Hospitals Birmingham NHS Foundation Trust and Betsi Cadwaladr University Health Board in North Wales all reported exceptionally high demand.
Flu linked to festive events
Christmas and new year gatherings may have caused a "bounce back" in winter viruses, according to NHS England.
On Thursday, NHS England revealed the number of people in hospital beds with flu averaged 2,924 each day during the week ending 4 January, up 9% from 2,676 the previous week.
The figure had previously been on a downward trend after reaching 3,140 in the week ending 14 December.
Figures also showed a sharp rise in the proportion of patients waiting at least 30 minutes in ambulances outside hospitals.
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Meanwhile, bed occupancy in England's hospitals was up 5% on the previous week at just under 92%.
A critical incident is defined as any local incident where the pressure or disruption is so severe that the NHS can no longer provide essential services safely or effectively.
Royal Surrey NHS Foundation Trust operates Royal Surrey County Hospital, Haslemere Hospital, Milford Hospital, Cranleigh village Hospital, Royal Surrey Cancer Centre, Royal Surrey Cancer Centre at East Surrey, Royal Surrey Cancer Centre at Ashford and St Peter's, and Royal Surrey Cancer Centre at Frimley.
Epsom and St Helier University Hospitals NHS Trust operates Epsom Hospital and St Helier Hospital, and runs services from other locations, including Sutton Hospital.
Surrey and Sussex Healthcare NHS Trust runs East Surrey Hospital near Redhill and also provides services at The Earlswood Centre, Caterham Dene Hospital, Crawley Hospital and Horsham Hospital.
East Kent Hospitals University NHS Foundation Trust runs Buckland Hospital, Estuary View medical centre, Kent and Canterbury Hospital, Queen Elizabeth The Queen Mother Hospital, Royal Victoria Hospital, and William Harvey Hospital.
(c) Sky News 2026: Four hospital trusts declare 'critical incidents' amid high demand as flu and norovirus cases surge

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