Causes

In many cases heartburn is caused by defective lower esophageal sphincter pressure. The esophageal sphincter is a group of muscles at the bottom of the esophagus which relaxes and opens to allow food into the stomach after swallowing and then increased pressure in the muscles closes the sphincter to prevent the stomach contents from going back up into the esophagus. Problems arise when:

• the sphincter spontaneously relaxes and opens at times that it shouldn't
• increased pressure from the stomach overpowers the pressure in the sphincter forcing stomach content up into the esophagus
• the sphincter has a naturally low pressure
• there is inadequate mucosal lining in the esophagus
• the stomach empties too slowly
• the esophagus empties too slowly
• there is a hiatal hernia
• foods lower sphincter pressure (i.e. peppermint, spearmint, chocolate, foods with high fat content, coffee, cola, tea, citrus juices, onions and garlic)
• smoking lowers sphincter pressure
• medications delay gastric emptying (i.e. theophylline, tricyclic antidepressants, beta blockers, anticholinergic agents
• too large a meal causes distension of the stomach
• pregnancy increases pressure in the abdominal area

There are a large number of factors which can cause heartburn and in most cases these are made worse by the acid reflux itself. For this reason it is important to treat the condition if it occurs frequently, to prevent worsening of the disease.