Readers of the BBC News website have been sharing their experiences of A&E.
It comes on the day that NHS figures were published, showing waiting times in England between October and December were the worst for a decade.
However, despite missing the target of seeing 95% of A&E patients within four hours, the performance in England is still better than elsewhere in the UK.
'The NHS is patently underfunded'
David Cunningham, 56, from Fareham in Hampshire describes what happened after his 81-year-old mother collapsed on Monday night.
"We dialled 999 at 21:07 requesting an ambulance. It didn't arrive until Tuesday morning - she spent more than 11 hours on the floor.
"She suffers from confusion but has problems with her legs following a hip replacement.
"My sister is a qualified nurse and was trying to comfort my mum. She phoned 999 four times. We were told it would be a two-hour wait, then four hours, then six.
"My father, who is in his nineties, was up all night looking out of the window to see if there was an ambulance.
"Free at the point of delivery? We haven't even got to the point of delivery.
"It's not acceptable. It's called an emergency service, and over 11 hours waiting is not an emergency service.
"I don't think the NHS is coping. It's patently underfunded."
'Patients don't feel distressed or let down'
Dr Gulliford works in acute medicine at Wrightington, Wigan and Leigh NHS Foundation Trust.
"I think there is an increasingly elderly population and, over time, these people are going to put greater demands on the healthcare system.
"We have seen a large number of people coming to A&E.
"The way to solve the problems - particularly when we hit winter and there is more flu virus, coughs, colds and pneumonias around - is through collaborative working and innovation.
"It's about thinking about working together as a team to find the best way to treat the patient in the right place at the right time.
"Morale generally in the A&E department at Wigan is still maintained.
"I've not got a sense that our patients are all feeling distressed or let down by the system locally.
"As long as we communicate to patients that there may be a delay in being seen sometimes at very busy periods, they are, in the main, quite accepting of that."
'The good has to be told'
Sue Drysdale, 58, is a bank clerk who recently attended Croydon University Hospital for a broken finger.
"I have nothing but praise for the staff there.
"I broke my finger in November and was going back and forth into hospital well into December as, at first, the fracture was not diagnosed.
"In A&E, you get a card if you should be seen earlier than some, which is a great idea.
"I was told to stay rather than go to minor injuries or anywhere else.
"I had a bit of a wait to see a triage nurse, but not too long. I waited around two and a half hours.
"There seemed to be a lot of people waiting who looked as if a GP visit would have sufficed.
"I can't fault my treatment. I think we need to stop knocking the NHS and try to find a way that would wheedle out the abusers of the service.
"I've seen staff getting abused and sworn at; sometimes the good has to be told.
"There were people who had been assessed as not being urgent, and if that's the case, of course there is going to be a bit of a wait."
'It was bedlam'
Richard Preston, 67, from Beckenham in Kent says he spent 20 hours on a trolley in A&E at Princess Royal University Hospital in Orpington, Kent, on 14 December 2014.
"I'd acquired a hacking cough and a temperature. Unfortunately, I've also got a low white blood cell count. It's a condition that means that if I begin to run a temperature, I need to contact my GP or a hospital.
"I rang NHS Direct, and after a conversation they told me to go straight to the Princess Royal.
"I got to A&E and went through triage. Over the phone I was told a doctor would be waiting to see me. When I got there it appeared there was an overlap. Triage put me in a queue with everybody else.
"Then I was taken through to A&E proper and another mini-triage. A&E had clearly been under pressure for some time. Reception were abrupt and told my wife and I we could be waiting for six or seven hours.
"After a blood test, I was put on a trolley and wheeled away. Because of my condition I need to be kept away from others.
"I got into a room at midnight and was there, on the trolley, until around 19:00 the following day.
"I was told that I was the youngest person there needing a bed, but that there wasn't a bed available.
"It was bedlam. There was a lot of noise. I could hear people coughing and a lot of activity throughout the night, including small children crying - it was fairly distressing.
"Staff were clearly under a lot of pressure. Food and drink were in short supply. I wasn't at all happy about being left in that situation."
6 January 2015 Last updated at 16:46