Almost half of specialist geriatric doctors think the NHS is institutionally ageist, according to a survey by Help the Aged.
Fifty-five per cent of doctors from the British Geriatrics Society said they themselves would be worried about how the NHS will treat them in old age.
Two thirds agreed that in their experience older people are less likely to have their symptoms fully investigated.
Seventy-two per cent said older people were also less likely to be considered and referred on for treatment.
The charity also found 77 per cent of society members would support introduction of legislation against age discrimination in the NHS.
The government has said age discrimination legislation will be part of the Equality Bill, but the charity has called for a review of the timetable, warning it could be over a year before the regulations are even drafted.