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.