45% of NHS trusts declared major alert last week
Some 45% of NHS trusts in England declared a major alert last week as services came under pressure.
Sixty-eight trusts out of 152 raised the alarm at least once due to bed shortages and problems managing the flow of patients through A&E.
Overall, NHS hospitals issued 294 operational alerts over the week from January 7 to 13, saying they were experiencing major pressures.
Some 27 trusts issued an alert on every single day.
The number of major alerts - previously called red and black alerts - cannot be compared with the previous week because NHS England has changed the way data is recorded.
Between January 9 and 15, there were also 52 occasions when A&E departments closed their doors to new patients - known as A&E diverts.
This compares to 39 the week before, between January 2 and 8.
There were also higher reports of the vomiting bug norovirus than this time last year, while flu cases have not yet reached their peak.
Hospitals have 95.8% of their beds full - up from 94.8% in the previous week and above the 95.2% for the same period last year. Anything above 85% increases the risk to patients from infection.
The data on norovirus shows there have been 3,049 cases in hospitals so far this year. This is 9% higher than the average number over the last five years, and 75% higher than the same period last year.
There have also been 1,305 cases of another bug, rotavirus. This is 21% higher than for the same period from 2013 to 2016.
As a result of the bugs, bed closures on wards have been much higher than last year though they are falling compared to previous weeks this winter.
Across the week, 82 people were admitted to intensive care or high dependency units with flu, while 11 people died from flu, taking the number of deaths this winter to 45.
An NHS England spokeswoman, said: "Demand moderated somewhat last week, but A&E departments remain under pressure, with flu cases set to increase and norovirus still higher than last year.
"As flu increases, we would remind the public that if you're otherwise healthy, usually you can manage flu symptoms yourself at home and there's no need to see a GP. Most people feel better within a week."
Official NHS guidance says a level 3 operational alert is when the local health and social care system "is experiencing major pressures compromising patient flow and continues to increase".
Level 4, the most serious, shows that pressure "continues to escalate, leaving organisations unable to deliver comprehensive care. There is increased potential for patient care and safety to be compromised".