The number of complaints made against NHS GPs and dentists have increased by 12 per cent in the past year, according to official figures.
Statistics from the NHS Information Centre show written complaints against dentists and doctors in England rose from 43,942 in 2007/8 to 48,597 in 2008/9.
They also reveal that patient complaints have soared by 28 per cent since Labour came to power in 1997/8.
Between April 2008 and March 2009, nearly 15,000 complaints were made over the standard of clinical care provided, including failures to diagnose illnesses or refer patients to specialists.
Almost as many concerns (11,003) related to poor communication and "attitude" of doctors, while 8,909 complaints were made regarding poor dental practice .
The Patients' Association said failings in out-of-hours services, difficulties getting an appointment with a GP, and problems finding an NHS dentist were likely to be the major factors behind the rise in complaints.
But many GP surgeries attributed the increase to their own efforts in making patients more aware of their right to complain.
Shadow health minister Mark Simmonds said the NHS figures were "extremely concerning".
