Patients are pressurising surgeons into recommending they have free NHS plastic surgery.
There are strict rules on who should have plastic surgery on the NHS
There are strict rules about who should receive operations such as breast enlargements, tummy tucks or nose jobs on the NHS.
But researchers suggest many women exaggerate the depression and unhappiness they feel in order to sway doctors' opinions, placing a significant financial burden on the NHS.
One surgeon said patients could "turn the screws" to get what they wanted.
Surgeons described the "emotional burden" they felt when denying treatment to patients who had waited months for a consultation and who then became "disappointed, emotional and angry".
One 37-year-old woman persuaded a surgeon that she was a suitable case for breast enlargement, despite a psychologist and a psychiatrist recommending she did not need the operation.
In another case, a 26-year-old who a psychologist had said was not a suitable candidate for breast surgery became so distressed as the consultation with a surgeon that he relented and agreed to operate.
Experts looked at the guidelines concerning the provision of plastic surgery in 32 health authorities and interviewed consultants from a regional plastic surgery and burns units.
The research published in the British Journal of Plastic Surgery, warns the trend places huge pressures on NHS funding.
Writing in the journal, the researchers, led by Professor Peter Salmon of the University of Liverpool, said: "Surgeons described feeling pressured to offer surgery by some patients'
emotional and insistent presentations, and believed that some patients contrived
their presentation in the attempt to elicit surgical decision
They suggested the existing guidelines needed to be more realistic and incorporate the patient's quality of life, to assist surgeons.
The researchers said cost, the degree of abnormality in the appearance and the importance of appearance in the patient's quality of life should be factors in the decision.
They added: "Future guidelines could thereby help to ensure access to cosmetic surgery
that is fair, reflecting patients' needs and surgical effectiveness, as well as
judgements about who merits limited resources."
The campaign group OCD Action, which supports people with Body Dysmorphic Disorder (BDD), a psychological condition where people believe their condition is abnormal.
A spokesperson told BBC News Online: "Surgeons should be cautious about proceeding with operations because if the person has BDD, surgery is rarely satisfactory and it could make the person more keen to have other operations."
She said others were affected by less severe feelings that changing a certain part of their body would make them happy.
"It's all about degree because everyone has appearance concerns. But with BDD, it becomes clinically significant."