Thousands of older people are missing out on potentially life-saving surgery because of outdated assumptions about fitness, according to a new report.
The study by the Royal College of Surgeons and Age UK said using age as a "shortcut" to assessing a patient's suitability for treatment should be scrapped.
Instead, it said decisions on whether older people are put forward for an operation should be based on their overall health - or 'biological age'.
The study, called Access All Ages, examines patterns of surgical treatment in relation to age in eight areas of surgery.
It shows that a patient's health needs, including surgery, increase with age, although the rates for such treatment decline as they get older.
The report has been welcomed by 82-year-old Kenneth Worden who was initially denied treatment for bladder cancer. He said it was considered "inappropriate" for someone of his age.
"He (the consultant) said it was incurable, untreatable and that was it … nothing he could do. An operation wasn't appropriate, whatever that means, and chemo was unsuitable and I was basically too old.
"I was in a blur. When you get devastating news like that your mind just switches off. I didn't think about anything really except that was it - goodbye world!"
It was only after his daughter Michele Halligan insisted on a second opinion that he was eventually given chemotherapy and an operation to remove his tumour.
Four years later Kenneth, of Huntington, Chester, is a regular at his local gym. He travels abroad frequently and is a keen rower.
His daughter said it was initially hard to challenge the first consultant, but she was determined to see if anything else could be done to save her father.
"I didn't want him to have inappropriate care but ... he didn't have any underlying disease process. He didn't even have high blood-pressure, he wasn't diabetic and he didn't have cardio-vascular disease. To me saying he was 78 was irrelevant," she said.
"In the past four years he's been on cruises, he's been five times to the States, he's back in the gym. He's bought himself a sports car. He goes out and about. Life's good."
The report warns that NHS cuts could disproportionately affect older people as clinicians might be tempted to question the cost effectiveness of providing treatment when life expectancy is shorter.
Michelle Mitchell, of Age UK , said "When it comes to people's health, their date of birth actually tells you very little.
"A healthy-living 80-year-old could literally run rings round someone many years younger who does not share the same good health.
"Yet in the past, too many medical decisions we believe have been made on age alone with informal 'cut-offs' imposed so that people over a certain age were denied treatment.
"This report shows the large gap between the number of people living with a condition or health need and the surgery rates to treat older people.
"We would like surgeons and other health professionals to read this report carefully and examine what they can do to ensure that age discrimination is eradicated from the NHS, as legislation now demands."
Health minister Dr Dan Poulter said: "The Government is committed to providing dignity in elderly care, and at the beginning of October we introduced an Age Discrimination Ban which means that all patients will receive a more personalised care service based on their individual needs - not their age."