In western countries, 25% of people report having heartburn at least once a month, 12% at least once per week, and 5% describe daily symptoms, state the authors of a Seminar in this week's issue of The Lancet.

Heartburn results from gastro-oesophageal reflux disease (GORD), where the contents of the stomach are pushed up into the oesophagus. Heartburn is more common in western populations than in non-western populations, write Nicholas Talley (Mayo Clinic College of Medicine, Rochester, MN, USA) and colleagues in their Seminar. In east Asian populations, for example, the prevalence is much lower than in western populations, with 11% reporting heartburn at least once per month, 4% weekly, and 2% having daily symptoms. The cause of the disease is currently unknown but genetic factors are likely to be important, state the authors. Lifestyle factors, such as obesity and smoking, may also increase a person's risk of developing GORD.

Professor Talley states: "Gastro-oesophageal reflux disease is a common problem and is expensive to manage in both primary and secondary care settings. The annual direct cost for managing the disease is estimated to be more than $9 billion dollars in the USA."