Gastroesophageal reflux is a disorder that result from abnormal amount of acid that moves back from the stomach up into the esophagus. This backward flow of acid may result in various typical and atypical symptoms. Heartburn and a sour taste in the mouth are considered typical symptoms, while chest pain, hoarseness, chronic cough, shortness of breath and others are atypical manifestations of GERD.

Up to 44% of the United States adult population experience heartburn at least once per month, 14% weekly and 7% daily. GERD is one of the most common disorders that is encountered by the gastroenterologist as well as the internist. Acid reflux results from a dysfunctional barrier between the stomach and esophagus. This barrier (sphincter is a specialized muscle in the lower end of the esophagus) between the stomach and the esophagus is either too weak to prevent acid from flowing back into the esophagus or unable to maintain its function as a barrier particularly after meals. The latter is an inappropriate relaxation of the sphincter for a longer period of time, exposing the esophagus to possible acid reflux. Other factors can contribute to the occurrence of acid reflux, such as hiatal hernia and slow stomach emptying.

For a long time investigators have noticed that stress is associated with worsening of GERD symptoms. In a Gallup poll, 64% of individuals with heartburn reported that stress increased their symptoms. To complicate matters even further, most patients with GERD (up to 80%) have typical symptoms of GERD but without any evidence of inflammation or damage to their esophagus. Could stress play an important role in generating symptoms in GERD patients in general and specifically in those with completely normal esophageal lining? An even more intriguing question with a possible therapeutic implication is how stress causes worsening of symptoms?

Initially, investigators raised the possibility that stress causes an increased number and duration of acid reflux events. However, when volunteers were exposed to acute stress in a laboratory setting, there was no evidence of increased frequency and duration of acid reflux as measured by a probe sensitive to changes in acid concentration that was placed close to the far end of the esophagus. Moreover, acid concentration was similar when patients with GERD that reported increased symptoms during stress were compared to those whose symptom response remain stable during stress. Further attempts to demonstrate increased acid exposure in the esophagus during stress have yielded negative results.

At this stage the attention of the investigators have switched to psychological profile assessment as the possible cause for stress-related symptom aggravation in GERD patients or at least a subset of them. Subsequently, it was found that patients with GERD, who are chronically anxious and are exposed to long periods of stress during everyday living are more likely to notice worsening of symptoms during stressful event. Most patients with GERD were found to be psychologically similar to patients without GERD, even though a significant subset of patients (up to 30%) was found to be psychologically distressed. It was then suggested that the general psychological distress affects symptom perception and how the disease presents in these individuals. Patients with GERD, without an esophageal inflammation in the esophagus, displayed more anxiety and hysteria. These patients also had less adequate social support structures.

In an interesting study from University of Alabama, patients with GERD were psychologically stressed by using a difficult computer video game and mental arithmetic. Participating subjects reported increased subjective ratings of anxiety and symptoms of GERD. The stressful task did not have an effect on acid concentration in the esophagus as has previously been reported.

Patients then underwent relaxation, using progressive muscle relaxation procedure (subjects alternately tensed and relaxed 16 muscle groups in sequence). Patients who received relaxation reported lower subjective rating of anxiety and acid reflux symptoms. Interestingly, during relaxation there was also a reduction in the concentration of acid in the esophagus. In this study the authors suggested that stress might affect GERD patients by reducing threshold for symptom generation. In other words, stress may cause an increase in esophageal sensitivity to smaller amounts of acid. In addition, this was the first study to show that relaxation per se can have a true physiological effect on the amount of esophageal acid exposure. Although this study helps us further understand the relationship between stress and GERD, the mechanism by which stess enhances sensitivity to acid remains to be determined. In a study we currently perform in our laboratory, acid is being infused in to the esophagus of patients with GERD that are simultaneously exposed to a psychological stressor. Preliminary results suggest the threshold for symptom generation is markedly reduced during stress as compared to baseline (off stress). Regardless if inflammation was present or absent in the esophagus, stress clearly led to an increased sensitivity to acid.

In summary, GERD patients that are stressed report worsening of typical heartburn symptoms. Psychological factors, such as anxiety and somatisation may play a role, particularly in those patients without esophageal inflammation. Increased esophageal sensitivity to acid appears to be the underlying mechanism. Future studies into brain mechanisms involved in visceral perception and stress response may provide a better understanding of brain-gut relationship and its effect on symptom perception. If you are interested in research studies on the relationship between stress and heartburn, please call (310) 312-9381.