Groin hernia patients are having to "prove their pain" and show they have complications to get surgery, the Royal College of Surgeons (RCS) has said.
In Kent and Medway, patients are having to show their hernia has grown larger or become "incarcerated" to access operations, the RCS claimed.
The RCS said harsher restrictions may amount to "rationing".
NHS Clinical Commissioners said patients took priority but the NHS did not have unlimited resources.
A groin hernia, or inguinal hernia, is when fat, intestines or other abdominal structures protrude through a hole in the abdominal muscles.
When the patient lies down the protruding part drops back, but sometimes it gets stuck or incarcerated.
Incarceration can then lead to strangulation - when the blood supply to a section of organ or tissue is cut off, which is life-threatening, the RCS said.
Freedom of information requests by the RCS and British Hernia Society (BHS) found:
- 52% (95 clinical commissioning groups or CCGs) require patients to suffer from pain or discomfort sufficient to impede everyday activities or working life before surgery is allowed
- 5% (8 CCGs all in Kent and Medway) require patients to demonstrate a history of incarceration and/or their hernia increasing in size from month to month to access surgery
- 24% (44 CCGs) had policies in line with clinical guidelines from the British Hernia Society and the Royal College of Surgeons
- Other CCGs did not have any form of restriction in place
RCS senior vice-president Susan Hill said: "It's difficult to prove categorically that these CCGs are introducing harsher restrictions for inguinal hernia surgery to make financial savings.
"However, we have seen a significant increase in CCGs that have acknowledged rationing surgery in other ways, for example by smoking status or BMI, to save money, so this may be the case here."
Calling on NHS England and ministers to intervene, she added: "Allowing commissioning groups, not patients with their surgeon, to make a decision to operate is putting patients at unnecessary risk of serious complications."
David Sanders, from the BHS, said patients were being denied access to a procedure that potentially limits pain and improves quality of life.
He said: "The NHS has to be very clear about what it offers.
"Does it want a value for money service with quality and safety as a priority, or a rationed service that will inevitably put some patients at risk?"
Dr Amanda Doyle, co-chair of NHS Clinical Commissioners, an independent body representing CCGs, said: "In cases where there is a high risk of complications or where patients are in persistent pain as a result of groin hernias, most CCGs will commission surgery."
She said elective hernia surgery was a common procedure but still carried risks, adding: "Clinicians need to carefully consider each individual case.
"Ensuring patients get the best possible care against a backdrop of spiralling demands, competing priorities and increasing financial pressures is one of the biggest issues CCGs face.
"On a daily basis they are forced to make difficult decisions that balance the needs of the individual against those of their entire local population.
"As a result there are some tough choices that have to be made."