Complaints about hospital treatment and community health services have reached their highest level in eight years in Scotland, prompting claims the NHS is feeling the strain of cuts to resources and staffing.
Some 8,117 complaints were made in 2011/12, up 1,062 in the space of 12 months, official figures revealed.
It is the largest increase since NHS procedures were revised in 2005 and is the equivalent of 22 complaints being lodged every day by patients.
Of the total complaints about hospital and community care, 77%, or 6,235, related to acute services in hospitals. This marked a 20% rise when set against the 2010/11 figure of 5,217.
In addition, 60% of the total complaints were either fully or partially upheld, a 12% increase on the year before.
But there was a large decrease in the number of complaints to the Scottish Ambulance Service, down 43% in a year.
Labour said the NHS is "buckling under the pressure that the SNP is putting on it" while the Tories said staff are "clearly feeling the strain of the various cutbacks being made by the Scottish Government".
A Scottish Government spokesman said: "Previous research showed that patients were reluctant to complain.
"The findings from the research helped inform the development of the Patient Rights (Scotland) Act 2011 which provides from April 1 2012 that all patients have a right to give feedback or comments, raise concerns or complaints about the health care they have received.
"Revised guidance will ensure that local processes are developed to encourage, welcome and view feedback, whether good or bad, as opportunities for improvement and to ensure the NHS provides person-centred care was issued in March."