A formal warning has been issued to the James Paget University Hospitals NHS Foundation Trust over its standards of care.
The Care Quality Commission (CQC) says the hospital trust must do more to improve standards of care or face "serious consequences".
Inspectors found that some of the Trust's records were not up to date and that it was failing to take the proper steps to protect patients from receiving inappropriate care.
Andrea Gordon, of CQC , said: “The law says that these are the standards that everyone should be able to expect. Providers have a duty to ensure they are compliant.
“We will be returning to the trust to follow up on progress and, when we do, we will expect the trust to be able to demonstrate it has made improvements.
“James Paget University Hospitals NHS Foundation Trust needs to address these issues or face serious consequences."