Gastro-oesophageal reflux disease (GORD) is defined as symptoms or mucosal damage (oesophagitis) resulting from the exposure of the distal oesophagus to refluxed gastric contents. However, the symptoms of reflux oesophagitis do not equate with mucosal damage, and patients with endoscopic evidence of oesophagitis do not necessarily have the worst symptoms.

In primary care GORD is therefore best thought of in terms of symptoms: symptom control is the aim of most management strategies, and indeed typical symptoms can guide doctors to the correct diagnosis. Since frequency and intensity of symptoms are poorly predictive of the severity of mucosal damage, with the converse also applying, endoscopy may be less useful than commonly perceived. A variety of other tests are available to diagnose and assess the severity of disease if symptoms are atypical and results of endoscopy normal.

Nevertheless, oesophagitis resulting from GORD has become the commonest single diagnosis resulting from endoscopy carried out for dyspepsia, although whether this represents a true increase in prevalence or simply reflects a change in referral practice is unclear. There is little doubt that a spectrum of severity of disease exists, with most affected people never consulting a doctor and only a minority with unremitting symptoms or complications from the disease receiving attention from hospital specialists. Consequently, treatment of patients presenting in general practice may not be best guided by the outcome of most clinical trials, which have recruited patients from those referred to hospital.