**2. Epidemiology**

In recent years, the global prevalence of GERD is increasing. Based on geographical, lifestyle, and diet habits, in different regions of the world varies from 2.5% to 51.2%. According to epidemiological research, the prevalence of GERD appears to be the highest in Southeast Europe and South Asia (more than 25%), and lowest in Canada, France, and Southeast Asia (below 10%) [2]. The prevalence of laryngopharyngeal reflux has also been constantly rising in the Western world and today affects an alarmingly high percentage of the general population. It is estimated that clinical presentation of LPR could be found in 5–30% of individuals [1]. About 10% of patients visiting ENT clinics have symptoms attributed to LPR, which is present in up to 50% of patients with voice disorders [3].

Symptoms and findings are mainly nonspecific and some physicians believe that LPR is over-diagnosed. In clinical practice, the possibility of over- or under-diagnosed LPR depends on numerous factors, including physician's experience, expertise, and knowledge, as well as diagnostic methods [4].
