Acid reflux, also known as
gastroesophageal reflux disease (GERD), is a condition where stomach acid flows back into the
esophagus. The esophagus is a long
tube that allows food and liquid to pass from the mouth into the stomach. At the top and bottom of the esophagus there are two ring-shaped muscles called the upper and lower
esophageal sphincters, respectively. Both sphincters relax during swallowing to allow the passage of food or liquids into the stomach, while the lower esophageal sphincter closes between meals to prevent the backflow of gastric acid. Acid reflux occurs when the lower esophageal sphincter (LES) does not close completely, allowing gastric acid to enter the esophagus and damage the esophageal mucosa.
Some degree of acid reflux is normal, especially after meals. However, when the pressure of the lower esophageal sphincter decreases, gastroesophageal reflux disease (GERD) can occur. Common symptoms of GERD include heartburn and regurgitation of stomach contents that mostly occurs after eating, when lying down, or when bending over. Other symptoms include retrosternal chest pain,
difficulty swallowing, persistent coughing, voice changes, and dental erosions. Over time, the presence of acid in the esophagus may damage the
esophageal lining and lead to
Barrett esophagus: a serious complication of GERD that increases the risk of
esophageal cancer.
GERD may be caused by a hiatal hernia, which is where part of the stomach and lower esophagus move from the abdomen into the chest through an opening in the diaphragm, thereby decreasing the pressure of the lower esophageal sphincter. Hiatal hernia is more common in individuals who are overweight or obese as well as in pregnant individuals due to increased pressure in the abdomen from the growing fetus. Risk factors for developing GERD also include those that weaken the lower esophageal sphincter, like certain foods, a fat-rich diet, caffeine, alcohol, and smoking. Finally, there are certain medications that can worsen acid reflux, such as antihistamines and calcium-channel blockers.
First-line treatment for GERD includes lifestyle changes and acid suppression therapy with antacids and proton pump inhibitors, such as omeprazole. In cases where conservative treatment is not effective, surgery may be necessary to tighten the lower esophageal sphincter.
