Hospitals are taking action to address structural concerns about seven buildings across England.
The Standing Committee on Structural Safety (SCOSS) issued guidance to NHS England after a sudden collapse of a flat roof at a school in Essex.
It said it believed the failure was caused by concrete planks, used in the construction of many buildings built between 1960s and the 1980s.
NHS England said checks were being carried out.
The affected hospitals are: West Suffolk, Hinchingbrooke in Cambridgeshire, James Paget and Queen Elizabeth in Norfolk, Airedale in West Yorkshire, Leighton in Cheshire and Frimley Park in Surrey.
Schools, government departments and local authorities were also made aware of the guidance in the SCOSS alert, that came out in May.
It said the reinforced autoclaved aerated concrete (RAAC) planks were made from a material "much weaker" than concrete.
The report said there was a "risk" with the planks but "its extent is uncertain". It advised if there was any doubt about their "structural adequacy" to replace them.
According to a 2018 board report, "ongoing structural issues", including corrosion, cracks and rust, were already identified at West Suffolk Hospital, built in 1973.
The hospital said it was carrying out "enhanced surveillance".
Chief executive Dr Stephen Dunn said: "The hospital is as safe as it can be but we will take continuous action to ensure we minimise the risk. Patient safety, staff safety is paramount."
The Queen Elizabeth Hospital said it was "accelerating" its case for upgrading or replacing its roof while Hinchingbrooke said a detail inspection of the site was due to begin in the coming weeks.
James Paget Hospital said its roof had been "extensively resurfaced" but checks were being carried out, with nothing found so far.
Mid Cheshire Hospitals Foundation Trust said investigations were taking place, as did Airedale Hospital. The BBC has approached Frimley Park Hospital for a comment.
NHS England said building maintenance and safety was the responsibility of the individual Trusts.