Emergency patients had the worst winter on record for being admitted to NHS hospitals in England, with nearly 200,000 waiting at least four hours.
Figures from the health service showed a near five-fold increase in the number of A&E patients suffering admission delays over the last five years.
Between December 2016 and February 2017, a total of 195,764 patients waited at least four hours - the NHS standard - to be admitted to hospital from A&E, up from 40,791 in 2011/12.
The figure is the highest since records began and marks a sharp spike on the winter months last year when 134,576 patients missed the four-hour target.
Total emergency admissions to NHS hospitals in England rose from 1.3 million in winter 2011/12 to 1.44 million in winter 2016/17.
Extreme waiting times also reached record levels, as nearly 2,000 patients were forced to wait at least 12 hours before being admitted to hospital from A&E this winter.
The 1,877 delays were a huge jump on the year before when 375 people waited 12 hours or more.
The NHS data comes as research suggests hospitals are creaking under the weight of demand.
A&E departments had to close their doors to ambulances almost twice as often this winter compared with the previous three years, a report from the Nuffield Trust showed.
The number of ambulance diverts in place at hospitals in England hit 478 for the three-month period from December to February.
This compares with an average of 249 over the same period in 2013/14, 2014/15 and 2015/16.
The number of days lost to so-called "bed-blockers" also hit record levels in England this winter.
A total of 577,195 days were lost through delayed transfers of care from December to February, compared with 471,780 in winter 2015/16.
Cancer referral rates were at their second lowest level on record, figures from February showed.
Only 79.8% of patients were seen within 62 days of an urgent GP referral, below the health service benchmark of 85%.
The lowest recorded level was 79.7% in January.
Surgeons warned that missed targets for planned surgery waiting times was on course to worsen after NHS England removed the measure from its list of priorities.
By the end of February, 90% of patients on the waiting list had been there for less than 18 weeks, below the standard of 92%.
This is a jump of 39% since the same time last year - equivalent to 103,505 patients.
Similarly, the number of patients forced to wait more than a year for planned surgery rose to its highest level since August 2012, at 1,583.
A Royal College of Surgeons spokeswoman said: "The NHS is under extreme pressure, trying to manage the huge financial strain while treating more and more patients.
"While we welcome some of the initiatives NHS England announced last month to help with pressures on planned operations, deprioritising the 18-week waiting time target for planned surgery risks undoing much of the progress the NHS has made on reducing long waiting times over the last decade."