Acid reflux, also known as Gastroesophageal Reflux Disease (GERD), is a digestive disorder where the acidic contents of the stomach reflux, or back up, into the esophagus. Acid reflux can cause a wide range of unpleasant symptoms, including heartburn, regurgitation, chest pain, difficulty swallowing, and a sore throat.
The exact cause of acid reflux is not known, however, certain factors can increase the risk of developing it. These include eating spicy or fatty foods, lying down after eating, drinking certain drinks (like alcohol and caffeine), smoking, being overweight, and certain medical conditions, such as a hiatal hernia or reactivation of the herpes virus.
Acid reflux begins when the lower esophageal sphincter (LES) does not close properly. The LES is a muscular valve located at the junction of the esophagus and the stomach. Normally, when you swallow, the LES relaxes and allows food to pass from the esophagus to the stomach. If the LES does not close properly, however, the acidic contents of the stomach can flow back up into the esophagus, causing acid reflux.
The refluxed acid can cause inflammation and damage to the lining of the esophagus, leading to painful and uncomfortable symptoms. However, in some cases, acid reflux can be more serious and even lead to complications like Barrett's esophagus and esophageal cancer.