Hundreds of thousands of patients are being sent home from hospital in the middle of the night, despite a promise to cut down on the practice.
More than 300,000 people have been discharged from hospitals between 11pm and 6am since 2012, an average of 400 a night.
Many of them are elderly, giving rise to concerns that vulnerable people may be unsafe or struggle to get home at unsociable hours.
The figures, uncovered through Freedom of Information requests by Sky News, revealed that in almost half of cases the proportion of patients discharged overnight also increased.
Some 72 of England's 160 NHS trusts provided figures for all three years, suggesting that the true number of patients discharged during the night is likely to be much higher.
Of the 72 trusts that replied, 152,472 patients were discharged between 11pm and 6am in 2011/12, rising to 152,479 in 2013/14.
The figures also revealed that 20,152 of those patients were aged over 75 in 2011/12; 19,728 in 2012/13 and 18,548 in 2013/14.
In 41 cases the number of patients discharged overnight increased, while in 31 cases the proportion of patients discharged between 11pm and 6am increased.
The proportion of patients discharged overnight remained the same at 2.41%.
In 2012 Sir Bruce Keogh, NHS England's medical director, called on hospitals to reduce the number of patients being discharged overnight.
He said at the time: "Patients should only be discharged when it's clinically appropriate, safe and convenient for them and their families.
''It is simply not fair to be sending people home late at night. We will look at this."
The NHS was accused of persisting in the widespread practice to help free up beds for other patients.
Dr Mike Smith, chairman of the Patients Association, told Sky News: "They have got people in A&E chomping at the bit, lying in corridors, they have got to be admitted and they have no beds.
"It's for the convenience of staff and the person they are admitting but at the gross detriment to the person they are chucking out."
Nadra Ahmed, chairwoman of the National Care Association, said discharged patients often ended up in care homes during the night.
She said: "They are going back without any relevant information about how their care might have changed, what the diagnosis might have been, their paperwork is not following because people are off duty and often without the relevant medication they need for the following day or even through the night."
A spokesman for NHS England told Sky News: "Discharging patients at night without appropriate support is unacceptable, particularly if a patient is vulnerable.
"Where a patient wishes to leave late at night or early in the morning, it should be accommodated only where it is safe and clinically appropriate and with the support of family, friends or carers. The decision to do this should always be based on what is best for the patient."
Jamie Reed MP, Labour's shadow health minister, criticised the prevalence of the issue.
"Under David Cameron, hospital wards are full to bursting," he said. "These figures show that in a desperate attempt to relieve the pressure, patients are facing this indignity."
He added: "Hospitals are operating above safe levels. Ministers promised to put an end to this practice two years ago, but it's getting worse. It's further proof you can't trust the Tories with the NHS."