Jean Driscoll, 72, was a healthy, active retiree, busy volunteering as a school governor and at her local hospital in Essex, England.
Two years ago, however, chest pains behind her sternum slowly developed into intense belches that never went away and brought Driscoll's life to a standstill.
"You think to yourself, 'I'm probably imagining it,' which we do when we get aches and pains sometimes," Driscoll said. "But [belching] is something, which has affected my whole life. I don't go out because it's embarrassing."
Driscoll, a former nurse and social worker, has given up her volunteering and much of her social life for a more private life at home.
Driscoll's son Steven, 36, with whom she lives, said friends and family help Driscoll shop, run errands or go to doctor's appointments. But practical support is all they can provide.
"It's not really affecting us in a bad way," her son said. "We're all just concerned for her and are wondering why it's taking doctors so long to do anything for her. We can't help her physically."
Nor can experts, it seems.
Driscoll said she has had a barrage of tests and medications in the last two years to see whether there was anything wrong with her stomach and intestines, including ultrasounds, barium-laced meals followed by X-rays, blood tests and tests for the bacterium H. pylori, a common culprit in digestive problems. All the results came back negative.
Alternative medicine techniques such as acupuncture and hypnosis also yielded no results.
"The tests are all negative, which is a very nice thing to happen," Driscoll said. "But it doesn't solve the problem and I've still got it."
A burp is a simple function designed to expel excess air from the stomach, air which we swallow while eating, drinking carbonated beverages or smoking, among other ways. People can even swallow air without realizing it. Too much air in the stomach can lead to excessive burping.
But Driscoll is not satisfied that her condition is related to swallowing too much air.
"You can't take in this much air all day and all night for two years," Driscoll said.
But Dr. Linda Lee, a clinical director of the Division of Gastroenterology and Hepatology at the Johns Hopkins Medical Institute in Baltimore, said the stomach is an adaptable organ.
"It's amazing what the human stomach can hold in terms of volume," she said. "Over time, the stomach can stretch out to hold large volumes."
Some people can swallow more air than they realize, and there are several common explanations for why.
Acid reflux, which occurs when stomach acids splash up to irritate the esophagus, can stimulate air swallowing to soothe the esophageal lining, even in the absence of other reflux symptoms such as heartburn.
"People tend to swallow a lot of air in response to the reflux," Lee said.
Food remnants in the stomach, which should empty after four hours, can contribute to acid reflux and stimulate unconscious air swallowing because of an intestinal blockage, a weak sphincter muscle or a nerve problem.
Dr. Ira Breite, a clinical assistant professor of medicine at the New York University Langone Medical Center, said he has seen about half a dozen patients in the last 10 years who burp chronically or almost chronically.