More than 71,000 patients were taken back to hospital last year just a day after they were sent home, figures have revealed.
The number of readmissions soared by a third in four years, figures revealed, with experts blaming a severe shortage of hospital beds.
They are concerned patients are being sent home before they have recovered to create room for others arriving from A&E.
The rise in 'emergency readmissions' has also been attributed to the escalating social care crisis, which has led to frail patients being discharged without access to the help they need at home.
More than 71,000 patients were taken back to hospital last year just a day after they were sent home, figures have revealed
The figures seen by the Mail were obtained by Healthwatch, a watchdog chaired by Sir Robert Francis, who led the inquiry into the Mid Staffordshire hospital scandal.
Sir Robert described the trend as 'troubling' and warned of 'significant distress' for patients and families, while charities said the pressure to free up beds had turned hospitals into 'conveyor belts', sometimes with tragic consequences.
The figures cover a snapshot sample of 70 hospital trusts in England. Assuming they are representative of the 150 English trusts, this means more than 150,000 patients could have been readmitted to hospital just one day after leaving last year.
Sir Robert said: 'Our research raised some big questions that affect the whole country and it's clear health and care leaders need to take a closer look at why people are returning so quickly.
'The fact emergency readmissions are growing without the causes being properly understood is troubling. While not all emergency readmissions can or should be prevented, they can cause significant distress for patients and families.'
Jeremy Hughes, chief executive of the Alzheimer's Society, said: 'Systemic pressures in the health and care systems, including the desire to free up beds faster, can turn hospitals into conveyor belts and threaten
