Receptionists could put people off seeing their doctor by inquiring about their symptoms, and need to deal "more sensitively with patients", a study has found.
The survey, published in the Journal of Public Health, found that 37% of men and 43% of women dislike having to talk to a GP receptionist about their illnesses.
About 42% of people said they found it difficult to get an appointment with a particular doctor or to get an appointment at a convenient time.
Roughly a third of people did not want to be seen as making a fuss.
About 2,000 people were questioned for the Cancer Awareness Measure analysis, which is run by Cancer Research UK.
"Diagnosing cancer early is something we have to take seriously, so anything that might prevent people from getting their symptoms checked needs to be overcome," said Dr Richard Roope, Cancer Research UK's GP expert.
"This may mean more emphasis on training front desk staff including receptionists to deal more sensitively with patients."
The study also found that those from socially deprived backgrounds were more likely to be put off the idea of describing symptoms than their wealthy counterparts.
They are also more likely to be put off if they are denied seeing their regular GP.
Speaking on Sky News Sunrise, Dr Monah Mansoori said: "All of it is a symptom of the lack of resources.
"I'm not surprised at all by this finding. It is a real problem.
"Another issue is that a lot of reception staff live locally.
"By virtue of what we do in healthcare it's a very personal thing. You're telling your deepest darkest problems and psychological issues and health concerns to someone in a confidential way."
While some experts say the receptionists' questions when patients book an appointment help identifying urgent cases, critics say untrained personnel should not triage patients.
Dr Maureen Baker, chairwoman of the Royal College of GPs, said: "With GPs making more patient consultations than ever before - 60 million more a year compared to five years ago - GP receptionists ensure the smooth-running of the practice and do their best to help patients see a particular GP at a suitable time for them.
"However, it is important to remember that they are not healthcare professionals, and are not in a position to make decisions about our patients' health."