Age discrimination is rife in England, with a quarter of over-50s taking part in a survey claiming they had been unfairly treated in stores, restaurants and hospitals.
Ageism also appeared to be linked to poorer health among those it affected, according to a new study.
Reported victims of age discrimination were more likely to suffer health problems, or develop them over time.
The findings are from the English Longitudinal Study of Ageing, which surveyed more than 7,500 people over the age of 50 and followed their progress for six years.
Participants were asked to respond to statements such as “you are treated with less respect or courtesy”, “you receive poorer service than other people in restaurants and stores”, and “you receive poorer service or treatment than other people from doctors or hospitals”.
They were also questioned about their experiences of being thought “not clever” or being threatened or harassed.
A total of 1,943 of the respondents said they had been affected by age discrimination.
Members of this group were more likely to rate their health as “fair or poor” than those who had not encountered ageism.
They were also more likely to suffer from depressive symptoms or debilitating long-term illnesses, and to go on to develop serious conditions such as diabetes, heart disease, or chronic lung disease.
The findings are published in The Lancet Public Health journal.
Author Dr Sarah Jackson, from University College London, said: “As a society, we need to increase public awareness of what constitutes ageism and how it can affect health and well-being so we can build collective movements, like those that brought about legislative and social change for other forms of discrimination.
“On a clinical level, raising the issue of age discrimination with older patients could help to identify those at risk of future health problems.”
Age discrimination in health services could mean that older patients are not receiving the best possible standard of care, the study suggests.
Age bias is a common feature of some treatments, according to the authors.
Older cancer patients are said to be less likely than their younger counterparts to receive potentially curative therapies, or to be included in trials for drugs to treat heart disease.
Another link between age discrimination and poor health is thought to be stress.
Previous studies have shown that discrimination can trigger stress responses that are harmful both to mental well-being and physical health.
People experiencing age discrimination may also resort to unhealthy behaviours such as smoking, drinking, and poor diet as coping mechanisms, the researchers said.
Commenting in the journal, Professor Martin Gulliford, from King’s College London, wrote: “The public health community has been slow to acknowledge the central role of discrimination in health inequality.
“Although the inter-relationships between age, socioeconomic status, health status and experienced discrimination are complex, these findings suggest that not only does age discrimination cause short-term psychological distress to older people, but could also have an important effect on their long-term mental and physical health.”
Louise Ansari, from the Centre for Ageing Better, said: “It is completely unacceptable that age discrimination should play a role in our society, but sadly it’s still all too common. And ageist attitudes and age discrimination don’t just affect your health.
“No-one in later life should be made to feel like a second class citizen.”