Gastroesophageal reflux disease (GERD), gastro-oesophageal reflux disease (GORD), gastric reflux disease, or acid reflux disease is chronic mucosal damage caused by stomach acid coming up from the stomach into the esophagus.
GERD is usually caused by changes in the barrier between the stomach and the esophagus, including abnormal relaxation of the lower esophageal sphincter, which normally holds the top of the stomach closed; another cause may be impaired expulsion of gastric reflux from the esophagus, or a hiatal hernia . These changes may be permanent or temporary ("transient").
In adults, the most common symptoms of GERD are heartburn, regurgitation, and trouble swallowing (dysphagia). Less common symptoms include painful swallowing (odynophagia), increased salivation (also known as water brash), nausea, and chest pain. GERD sometimes causes injury of the esophagus.
GERD in Infants and Children
GERD may be difficult to detect in infants and children, since they cannot describe what they are feeling and indicators must be observed. Symptoms may vary from typical adult symptoms. GERD in children may cause repeated vomiting, effortless spitting up, coughing, and other respiratory problems such as wheezing. Inconsolable crying, refusing food, crying for food and then pulling off the bottle or breast only to cry for it again, failure to gain adequate weight, bad breath, and belching or burping are also common. Children may have one symptom or many; no single symptom is universal in all children with GERD.
It is estimated that of the approximately four million babies born in the U.S. each year, up to 35 percent of them may have difficulties with reflux in the first few months of their life, known as spitting up. One theory for this is the "4th trimester theory" which notes that most animals are born with significant mobility, but humans are relatively helpless at birth; this suggests that there may have once been a fourth trimester, but children began to be born earlier, evolutionarily, to accommodate the development of larger heads and brains and allow them to pass through the birth canal and this leaves them with partially undeveloped digestive systems.
Most children will outgrow their reflux by their first birthday. However, a small but significant number of them will not outgrow the condition. This is particularly true where there is a family history of GERD present.
GERD may lead to Barrett's esophagus, a type of intestinal metaplasia, which is in turn a precursor condition for carcinoma. The risk of progression from Barrett's to dysplasia is uncertain but is estimated at about 20 percent of cases. Due to the risk of chronic heartburn progressing to Barrett's, EGD every five years is recommended for patients with chronic heartburn, or who take drugs for chronic GERD.
GERD is caused by a failure of the cardia. In healthy patients, the Angle of His—the angle at which the esophagus enters the stomach—creates a valve that prevents duodenal bile, enzymes, and stomach acid from traveling back into the esophagus where they can cause burning and inflammation of sensitive esophageal tissue.
Factors that can contribute to GERD include:
- Hiatal hernia, which increases the likelihood of GERD due to mechanical and motility factors
- Obesity: increasing body mass index is associated with more severe GERD. In a large series of 2000 patients with symptomatic reflux disease, it has been shown that 13 percent of changes in esophageal acid exposure is attributable to changes in body mass index
- Zollinger-Ellison syndrome, which can be present with increased gastric acidity due to gastrin production.
- Hypercalcemia, which can increase gastrin production, leading to increased acidity
- Scleroderma and systemic sclerosis, which can feature esophageal dysmotility
- The use of medicines such as prednisolone
- Visceroptosis or Glénard syndrome, in which the stomach has sunk in the abdomen upsetting the motility and acid secretion of the stomach
In 1999, a review of existing studies found that, on average, 40 percent of GERD patients also had H. pylori infection. The eradication of H. pylori can lead to an increase in acid secretion, leading to the question of whether H. pylori-infected GERD patients are any different than non-infected GERD patients. A double-blind study in 2004 found no clinically significant difference between these two types of patients with regard to the subjective or objective measures of disease severity.
Three types of treatments exist for GERD. These include lifestyle modifications, medications, and surgery.
Certain foods and lifestyle are considered to promote gastroesophageal reflux, but a 2006 review suggested that evidence for most dietary interventions is anecdotal; only weight loss and elevating the head of the bed were supported by evidence. A subsequent randomized crossover study showed improvement when avoiding eating two hours before bedtime.