Chest pain that is not explained by reflux disease or cardiac, musculoskeletal, mucosal, or motor esophageal abnormalities is classified as functional chest pain (FCP). Population-based studies reported that the prevalence of NCCP ranges between 19.0–33.0% in the general adult population. 

Rome IV Diagnostic Criteria for FCP :

1. Retrosternal chest pain or discomfort**
2. Absence of associated esophageal symptoms, such as heartburn and dysphagia
3. Absence of evidence that gastroesophageal reflux or eosinophilic esophagitis is the cause of the symptom
4. Absence of major esophageal motor disorders†

          *Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis with a frequency of at least once a week
        **Cardiac causes should be ruled out of this
          †Achalasia/EGJ outflow obstruction, diffuse esophageal spasm, jackhammer esophagus, absent peristalsis.