There is a wide variety in the ways complaints are being handled across the NHS, primary care and social care services in England, the Care Quality Commission (CQC) has found.
The report from the CQC found that many complainants were met with a "defensive culture" rather than being listened to and lessons being learnt.
The report noted that there was considerable variation with some exhibiting a high standard of good practice.
The reported noted that within adult social care and primary care many providers said they were receiving few complaints, suggesting a more open culture is needed.
In both the NHS and care the report found there was often a lack of timeliness and complainants left feeling their concerns were either not taken seriously or inadequately addressed.
Prof Sir Mike Richards, chief inspector of hospitals at the CQC who has led the review said: "A service that is safe, responsive and well-led will treat every concern as an opportunity to improve, will encourage its staff to raise concerns without fear of reprisal, and will respond to complaints openly and honestly.
"Unfortunately this is not happening everywhere. While most providers have complaints systems in place, people's experiences of these are not consistently good.
"We know from the thousands of people who contact CQC every year that many people do not even get as far as making a complaint as they are put off by the confusing system or worried about the impact that complaining might have on their or their loved one's care.
"More needs to be done to encourage an open culture where concerns are welcomed and learned from.
"Through our inspections, we have a big role to play in supporting this change. We will continue to hold health and adult social care services to the high standards that people both expect and deserve."
