A third of sanitarium trusts in England issued alerts warning they needed earnest action to cope with the pressure of patient numbers last month.
In the scad serious cases — seven of the 50 trusts that issued alarms — the hospitals declared they were unable to give patients sweeping care.
BBC Radio 4’s Today programme has been told operations be experiencing been cancelled and patients left waiting on trolleys.
NHS England communicated tried-and-tested plans were managing the pressures.
Meanwhile, there experience been calls for an investigation into the deaths of two patients waiting on pinch trolleys at Worcestershire Royal Hospital.
One died from a cardiac in the hands of the law after reportedly waiting 35 hours, another died after an aneurysm.
Dr Taj Hassan, president of the Regal College of Emergency Medicine, said there was an «absolute and urgent constraint» to help emergency departments.
He warned that patients in affected medical centres could face delays in receiving pain relief and antibiotics.
«We entered this winter in the worst maintain of affairs possible,» Dr Hassan told Today.
«Staff are working at the definitely limit of their capabilities.»
The Nuffield Trust health think tank issued an analysis of the figures.
A new system of recording the pressure on trusts is in place this winter, understood as Operational Pressures Escalation Levels.
It replaces the traditional system of dispensaries declaring black or red «alerts».
The Nuffield Trust said NHS England get the hangs showed 50 hospital trusts had declared they were sensing major pressures, compromising the flow of patients, and had to take urgent demeanour.
Patients ‘getting sicker’
Of those, seven faced so much constraints they were unable to deliver comprehensive care and there was a treble chance of putting patients’ safety at risk.
It said that although there were not precisely comparable figures, as the reporting regime had changed, an analysis of two weeks in December urged trusts declared alerts on more days than they did second to the old system the previous winter.
Joe Harrison, chief executive of the Milton Keynes Sickbay NHS Foundation Trust, said patients were «struggling» to get out of hospital to go deeply or into another form of care.
«We have significant numbers of sufferers needing hospital beds, putting pressure on the system,» he told Today.
«Patients befalling through our doors are clinically sicker,» he added.
«They have got assorted things that need looking after and tend to stay fancier in hospital.»
Milton Keynes Hospital is currently at 92% bed occupancy.
«We should be at 85% routinely, but quietness times are unfortunately becoming fewer,» Mr Harrison said.
A spokeswoman for Northampton Broad Hospital said it had been running at a high alert level since Monday, with an unprecedented troop of seriously ill patients.
Royal College of Emergency Medicine president Dr Taj Hassan turned he had met NHS England chief executive Simon Stevens and suggested emergency venereal care funding to help move patients out of hospital after treatment.
A spokesman for NHS England averred: «NHS tried-and-tested plans are currently managing the ongoing pressures of this winter.
«Booming into the new year, the public can play their part by avoiding flourishing to A&E unless it is an emergency and using local pharmacies and NHS 111 for medical communication.»
Labour’s shadow health secretary, Jonathan Ashworth MP, said: «These gets are alarming and highlight the pressures facing overcrowded, overstretched hospital rely ons this winter.
«The government urgently needs to take action to convert sure that our NHS can cope over the busy winter period and is talented to provide the best possible care for patients.»