Gastritis is an inflammation and irritation of the gastric mucosae. Causes can vary, as some drugs, alcohol and even microorganisms such as Helicobacter pylori can cause it. The main symptoms are heartburn, epigastric abdominal pain, nausea and vomiting.
Gastroesophageal reflux disease (GERD) is another type of inflammation of the gastrointestinal mucosae, in this case, the oesophagus, and occurs when the lower oesophageal sphincter (cardia) is not completely closed, allowing acid and other substances in stomach and digestive tract back into the oesophagus, causing irritation and inflammation. It is presented as retrosternal burning or bitterness in the throat, which is called heartburn. If this continues over time, it can cause serious injuries, such as oesophageal ulcers and Barrett's oesophagus.