The discomfort and pain of heartburn is caused when the lining of the esophagus, also known as the food pipe, comes into contact with digestive enzymes and stomach acid for an extended period of time.
The muscles at both ends of the esophagus, called esophageal sphincters, relax to let food pass, then tighten to keep stomach acid down. When the lower esophageal sphincter (LES) malfunctions and does not tighten enough, acid can wash up or "reflux" from the stomach into the esophagus, causing heartburn.
Some people also suffer from heartburn or chest pain due to a hiatal hernia, which is an opening in the diaphragm that allows a portion of the stomach to protrude into the chest. This defect can be acquired over time from straining, coughing or gaining weight.
When the stomach is in its normal position, the diaphragm and the lower esophageal sphincter work together to keep stomach contents and acid from rising up into the esophagus. When a hiatal hernia is present, acid and non-acid reflux can occur more easily.
Persistent reflux or heartburn that occurs more than twice a week is considered gastroesophageal reflux disease (GERD), and it can eventually lead to more serious health problems.
Other factors that may contribute to heartburn include:
- Obesity
- Pregnancy
- Smoking
Types of food that commonly worsen reflux symptoms include:
- Citrus fruits
- Chocolate
- Beverages containing caffeine or alcohol
- Fatty and fried foods
- Garlic and onions
- Mint flavoring
- Spicy foods
- Tomato-based foods, such as spaghetti sauce, salsa, chili and pizza