Repeated hiccup attacks combined with loss of weight and swallowing difficulties could signal cancer, an Irish researcher has said.
Professor Tom Walsh said nature of the tumour was changing
Professor Tom Walsh of the James Connolly Memorial Hospital in Dublin said some patients with oesophageal cancer complained of persistent hiccups.
More people die from the condition than are killed on the Republic of Ireland's roads, he said.
However, the majority of people do not know where the oesophagus is and many cannot pronounce the word, said the professor.
"Hiccups can accompany quite a wide range of different conditions," he told BBC Radio Ulster.
"This is one of the nastiest forms of cancer because it has such a high mortality rate.
"The majority of patients have symptoms for more than three months and they have lost a stone in weight before they present for investigations.
"We are trying to get the message across that patients should not ignore the early warning symptoms - difficulty swallowing, food catching on swallowing, especially accompanied by weight loss, and now in the presence of hiccups."
Professor Walsh said the nature of the oesophagus tumour had "changed dramatically".
"Whereas in the past, the type of tumour we suffered from was associated with a lifestyle of smoking and drinking, the modern tumour is associated with heartburn, reflux and regurgitation - associated with what people say is the good life."
In Professor Walsh's study of 99 patients with the disease, 27% complained of persistent hiccups and 6% said it prompted them to see a doctor.
He believes hiccups in cancer patients could be linked to the phrenic nerve - the motor nerve of the diaphragm.
"Nobody knows why, but there may be the involvement of the vagus nerve or the phrenic nerve," he said.