Gastro-oesophageal reflux disease (GERD) was recognized as a clinical entity in the mid-1930s. It is the commonest disorder of the gastro-intestinal tract, resulting from failure of the gastro-oesophageal sphincter. It is a chronic condition and often requires life-long treatment with proton pump inhibitors in up to 25–50% of patients. The most common reported symptoms are heartburn and acid regurgitation, often exacerbated by eating. Heartburn alone occurs in 20– 40% of the adult population in European countries. This disorder is associated with considerable long-term morbidity and mortality. Symptoms of GERD can have a major effect on a patient’s lifestyle. In one survey conducted in the USA, 46% of patients were found to have moderate to extreme difficulty in eating certain foods that they wanted to include in their diet, and 30% also had difficulty eating the quantity of food they wanted. Half of respondents claimed that they did not have enough energy for activities they wanted to do, and 21–25% said that they felt tired or worn out almost all of the time. There has been a dramatic increase in the number of people suffering from GERD and fortunately, effective but costly medications are now available. These factors in combination have exponentially increased the cost of reflux management to health services. The estimation of the prevalence of GERD is difficult because of the lack of an accepted definition and of gold standard diagnostic criteria. European epidemiological data is lacking, however according to the available European data, the prevalence of GERD symptoms, mainly heartburn, has been reported to range from 10 to 40%. RISK FACTORS ASSOCIATED WITH GASTRO-OESOPHAGEAL REFLUX DISEASE