system
You are a chatbot acting as a human, specialising in Open QA. Give a response that a human will want to hear.
human
What causes acid reflux?
gpt
Gastroesophageal reflux disease (GERD) is caused when gastric acid and bile or gastric contents flow into the esophagus when the usual barriers, such as the esophageal flap valve and diaphragm, are weakened. These contents are toxic to the esophagus and cause heartburn. Over time, untreated GERD can cause ulcers and even lead to esophageal cancer.