The regulator states that in England the quality of services provided to people across the health and care sectors has started suffering.
Data from about 13,000 inspections was looked at and the warning from the Care Quality Commission's (CQC) followed.
According to the regulator, everyone from hospital to care homes was struggling due to complex cases rising and pressure on staff.
There are 16 key standards and one in every four failed at least one in 16.
Standards relating to respect, dignity, welfare, care and nutrition were the areas that failed the most. Workforce included both numbers and skills of staff.
Staff could not pay individual attention to people it was looking after due to the pressures on the system.
To-do lists were something that the staff was looking at to take up their daily responsibilities.
The CQC said, "A culture was created in places that were struggling where the unacceptable becomes the norm."
CQC chief executive David Behan said, "Despite the pressures there was no excuse for poor performance. Health and care services need to rise to the challenge."