Record numbers of people have experienced long waits in A&E, figures show.
Waits of more than 12 hours among elderly people have more than doubled in two years, according to NHS Digital data.
It shows a huge jump in the number of long waits among those aged 70 and over - from 34,088 in 2013/14 to 88,252 in 2015/16.
Among all ages, there were 185,017 waits of 12 hours or more in 2015/16 - up from 157,895 the year before and 87,213 in 2013/14.
Of the waits in 2015/16, 56,013 were for people over the age of 80.
Separate figures form NHS Improvement, obtained by the BBC, show unprecedented long waits last week in A&E departments across England.
More than 18,000 patients waited longer than four hours for a bed, with 485 waiting more than 12 hours - treble the number for the whole of January last year.
The data suggests about one in five patients admitted for further treatment endured a long wait on trolleys and in hospital corridors - twice the normal rate.
Since the start of December, hospitals have seen only 82.3% of patients who attended A&E within the four-hour target. That is the worst performance since the target of 95% was introduced in 2004.
Chris Hopson, of NHS Providers, which represents hospitals, said this was not down to "ordinary winter pressures".
He told the BBC: "Trusts are really struggling."
Mark Holland, from the Society for Acute Medicine, said the "NHS in England is now performing at an all-time low" and this was predicted months ago.
He said: "We again call on the Secretary of State for Health to acknowledge the crisis we now face. Urgent action is needed.
"This is not a 'winter' crisis. This is a blizzard in an eternal winter of the NHS.
"This situation we have reached was entirely predictable."
Chris Moulton, vice president of the Royal College of Emergency Medicine, said of the NHS Digital data: "These figures demonstrate that we don't have enough acute hospital beds or enough social care for a growing and ageing population.
"These elderly people are on trolleys, waiting for a bed.
"These figures are from the time people arrive at A&E and show just how bad things are."
Shadow health secretary Jonathan Ashworth said: "It is extremely worrying to see that older people are being left to wait for such unacceptably long periods of time on trolleys in our hospitals.
"This is yet another clear signal that hospitals are struggling to cope with the crisis engulfing our NHS this winter."
Prime Minister Theresa May's spokeswoman said the Government was delivering the funding requested by the NHS in its five-year plan.
She added: "It is not unusual to see particular pressures on the NHS during a winter period."
Health Secretary Jeremy Hunt refused to answer questions from reporters as he headed to a summit on patient safety.
On Monday, he suggested he might alter the four-hour target for patients in A&E, saying it should only apply to the most urgent cases.
Mr Hunt told MPs in the Commons that up to a third of patients do not need to be seen in A&E. In 2014, Mr Hunt took his own children to A&E because he did not want to wait to see a GP.
Data published by NHS Digital shows 37% of people going to A&E are discharged with no follow-up needed, while 20% are discharged to their GP and 20% are admitted to hospital. Monday is the busiest day of the week.
Mr Moulton said there were many valid cases among the 37% of people discharged with no follow-up.
He said: "Many people go to A&E departments and leave with the advice and reassurance they need.
"An example is a child who has been taken to A&E with a big lump on their head after falling over. We might check them over and say we think they're okay and they are discharged, but that is still a good and valid use of an emergency department's time.
"Even if we did get rid of that 37% of people from A&E, it still wouldn't do anything about these old people laying on trolleys waiting for beds."
Figures from the Royal College of Emergency Medicine show that 40% of the 60 hospital trusts it is monitoring were seeing less than 75% of patients within the four-hour target.
It said A&E departments were overcrowded and there was a "heightened risk of safety being compromised".
The college said it "strongly believes" the four-hour target is a vital measure of performance and safety.
President Dr Taj Hassan said it was patients who present with emergencies who are posing the greatest problems.
He said Mr Hunt should not be seeking to target patients with minor illnesses, adding that this was "not the priority".