The Health Age -- Heartburn is caused by hydrochloric acid fund in stomach juices. One among three people is affected by heartburn some times in their life. This acid is produced by stomach to break down the food. A small muscle known as oesophageal sphincter prevents acid from flowing back up the oesophagus and works as one way valve to control the flow of food into the stomach. When oesophageal sphincter does not work properly, acid can leak into the oesophagus and causing heartburn.
