More than one in four health and social care providers are failing to meet essential standards of quality and safety, the health watchdog found.
The Care Quality Commission (CQC) said it had to take action to improve standards in 27% of locations it inspected.
The CQC report, which is based on findings from unannounced inspections of 14,000 health and social care providers in England, said it had to instruct 3,687 organisations to improve services.
In extreme cases, services had to be completely shut down while others were given improvement plans.
It said that 77% of NHS services were providing the essential standards, compared to 72% locations in adult social care and 82% in independent healthcare.
The CQC said the key problems found upon inspection were the mismanagement of medicines, staffing numbers and record keeping.
Almost two in five locations failed to meet the essential standard of medicine management.
"Our inspectors are seeing a worrying number of examples where safe management of medicines is being compromised, often by a lack of information given either to those taking the medicines, or those caring for them," the authors of the report said.
One in 10 organisations failed to meet the appropriate staffing levels and 15% of locations had poor record keeping.
The report states: "Issues range from records - which include crucial information about people's care - being incomplete or not up-to-date; not kept securely or confidentially; or not showing that risks to people had been identified and were being managed appropriately."
The inspectors also raised concerns about the premises used for social care.
CQC's deputy chief executive Jill Finney said: "The data that CQC holds on performance across health and social care is unique in breadth and scale.
"In our first market report, we use this data to look at patterns of performance across sectors, at the specific areas where providers are failing to meet people's needs - and we describe the action we've taken to hold providers to account for these failings.
"We've also asked inspectors - our eyes and ears on the ground - if there are other emerging trends that are not yet apparent in terms of numbers, but are causing them concern. This adds another dimension to our assessment of risk and where we need to focus our attention - we hope this intelligence will also be useful to other parts of the health and social care system.
"Now that we've collected a significant amount of inspection data, we can use this information to probe more deeply into what lies behind risks in the system - this report is the first step in that process.
"CQC will use this information to help target our unannounced inspections - but we also want providers to look closely at this report in order to assure themselves that they are taking all steps necessary to protect people from poor care."
Royal College of Nursing chief executive and general secretary Dr Peter Carter said: "It is shocking that more than one in four locations inspected in this report have failed to meet even essential standards of quality and safety.
"We are reassured that the CQC has taken action to address these failings; nevertheless, this presents a long overdue wake-up call for the Government. Those locations in question must be brought up to standard as a matter of urgency."
Health Minister Simon Burns said: "There is no excuse for delivering anything but the best care.
"By exposing poor practice and shining a light on best practice we are determined to drive up standards for everyone.
"Our modernisation plans for the NHS and social care are designed to lift care far above these minimum standards of safety and quality, establishing services which are among the very best in the world."