More organs from higher risk donors are being used for transplants because of a donor shortage, the BBC has learned.
Organs from patients with a history of cancer or drug abuse, elderly donors and those with serious illnesses have to be considered, say surgeons.
They say they face a dilemma of leaving people to die without a transplant or operating with organs from such donors.
The use of higher risk donors has doubled from 13% in 1998 to 26% last year, BBC Radio File on 4 was told.
An average of three patients a day are dying in the UK because of a lack of a suitable organ for transplant.
This means surgeons are having to use organs from donors they call "marginal", meaning they come from the following categories: the over-70s, patients with serious illnesses, patients with a history of cancer or drug abuse, or drinkers and heavy smokers.
Professor James Neuberger, medical director of NHS Blood and Transplant, which co-ordinates the supply of organs, told File on 4: "There is no doubt that if we had more donor organs... we could be a lot more selective about those that are used."
He added: "In some cases this is completely safe for the patient but we're certainly seeing organs from higher risk donors being used in order to meet the ever growing need for organ transplantation."
He said in an ideal world surgeons would not use organs that carried added risks but the alternative was more deaths of patients on the transplant waiting list.
Statistics seen by File on 4 show that in 1998 13% of 787 donors were in the marginal category, but by 2008 the percentage had doubled to 26% of 899 donors.
Surgeon Simon Bramhall, who carries out liver transplants at the Queen Elizabeth Hospital, Birmingham, said factors such as seatbelt laws and road safety improvements had reduced the number of organs available from young donors.
"I've taken organs from a number of donors in their 80s and transplanted them successfully," he said.
He said "beggars can't be choosers", but added: "The donors are getting older, they're getting fatter and they're having more of what I call co-morbid disease - additional diseases like heart disease, lung disease and even kidney disease."
One patient who was given a kidney, which turned out to be cancerous and had to be removed, told File on 4 she had been so traumatised by the experience she had refused to put her name back on the transplant waiting list.
The woman said: "I felt as though my life had been ruined. I felt destroyed, my family was destroyed... my husband has to care for me now. When I was on dialysis before I was coping, now dialysis is worse."
File on 4 is on BBC Radio 4 on Tuesday, 24 November, at 2000 GMT, repeated Sunday, 29 November, at 1700. You can also listen via the BBC iPlayer after broadcast or download the podcast.