If you're one of these people, you may be suffering from what is known as GORD, of which heartburn is a symptom.
See the difference between erosive GORD and functional heartburn below:
GORD is an abbreviation for gastro-oesophageal reflux disease. It describes a spectrum of clinical conditions in which stomach acid pushes up through the lower oesophageal sphincter into the oesophagus. (The oesophagus is the tube that connects the mouth to the stomach; this is also called the gullet.)
Most people experience reflux from time to time, and it's only when symptoms become frequent (more than twice a week) that GORD may be diagnosed.
Heartburn is the most common symptom of GORD, and involves a painful burning sensation in the stomach and chest after eating. Despite its name, the symptom has nothing to do with the heart.
The other two common symptoms of GORD are acid reflux/regurgitation (where the stomach acid flows back into the mouth) and dysphagia (painful and difficult swallowing).