Patients should be refused treatment because of their age in some cases, government advisers have proposed.
Campaigners are against age discrimination in the NHS
Where age can affect the benefits or risks of treatment, discrimination is appropriate, the National Institute for Health and Clinical Excellence said.
It rejected taking other social and lifestyle issues like obesity into account over access to treatment.
Charities representing older people said the recommendations were outrageous and sent out mixed messages.
The National Institute for Health and Clinical Excellence (Nice) looked at whether lifestyle issues were relevant to how effective a drug will be and the effect on value for money.
Its draft recommendations said there was no case for discrimination on the basis of gender and sexual orientation.
It also said discrimination against patients with conditions which are self-inflicted should be avoided, effectively ruling out restrictions on access for people who smoke or are obese.
However, the recommendations say that where age is an indicator of benefit or risk, age discrimination is appropriate.
Michelle Mitchell of Age Concern said this "should never happen".
"Nice is in danger of sending very mixed messages, and it is older people who will lose out.
"They already suffer age discrimination in health and social care as it is."
Ms Mitchell said a survey of GPs by the charity had found that 80% thought age-based rationing already happened in the NHS.
Marie Kamara, 75, whose sister died aged 71 of breast cancer, said it was unfair.
Women over the age of 50 receive regular invites for breast screening, but that stops at 70.
Ms Kamara said: "Who decides? Is it somthieng to do with finances? Is it a lack of respect of the elderly? I don't know. I can't really work it out."
Stephen Jackson, professor of clinical gerontology at King's College, agreed age discrimination was already happening.
He said certain courses of treatment may well pose greater risks for older patients, but that it should be up to them to decide whether to take that risk.
But a spokesman for Nice said age discrimination could work both ways, with some treatment being made available only to older people.
He cited some flu drugs, which are only given to over 65s.