Gastroesophageal reflux disease (GERD) is a chronic medical condition caused by the repeated backup or regurgitation of food and digestive acid from the stomach into the oesophagus from the mouth to the stomach. It can result from a defective sphincter between the oesophagus and the stomach (called the lower oesophageal sphincter or LES). The most common symptoms suggestive of GERD are heartburn or acid indigestion. In addition to increasing the risk of oesophageal cancer, GERD causes significant impairments to health-related quality of life.
Almost 38 million Americans experience the discomforts of gastroesophageal reflux disease at least once a week, comprising 15% of women and 13% of men. More than 27 million of these have symptoms at night, resulting in impairments of pain, mental health, social functioning and vitality similar to those reported by patients with more serious chronic conditions such as angina or congestive heart disease. Obesity is an independent risk factor for GERD, because it increases intra-abdominal pressure and causes dysfunction of the lower esophageal sphincter (LES).
Since 2010, more than four hundred scientific articles concerned with the connection between asthma and gastric acidity have been published. One of the most common features of asthma, in addition to wheezing, is gastroesophageal reflux. When acid gets into the windpipe, there is a tenfold drop in the ability of the lungs to take in and breathe out air. It is estimated that between up to 80 percent of people with asthma also have GERD. Compared with healthy people, those with asthma also have significantly more reflux episodes and more acid-induced irritation of their oesophageal lining.