Risk Factors

Conditions that cause difficulty with digestion can increase the risk of heartburn. These conditions tend to make it easier for food to back up into the esophagus, causing your heartburn. Conditions include:

• Obesity. Some doctors believe obesity may play a role. Extra weight exerts pressure on the stomach and diaphragm, which separates your chest and abdomen. This pressure allows stomach acids to back up into your esophagus.
• Pregnancy. Pregnancy puts pressure on the stomach. Some believe hormones also contribute to heartburn by relaxing muscles such as the lower esophageal sphincter (LES), the valve that keeps stomach acid out of the esophagus.
• Hiatal hernia. When part of your stomach protrudes into your lower chest, you have a hiatal hernia, which can worsen your heartburn by weakening the LES. Hiatal hernias are common, occurring in about a quarter of people older than 50. They do not always have symptoms. However, large hiatal hernias can cause heartburn and chest pain. Medications and lifestyle changes can help.
• Peptic ulcer. Often caused by bacteria called Helicobacter pylori (H. pylori), an erosion or scar near the stomach valve (pylorus) can keep this valve from working properly or can obstruct food. Food doesn't empty from your stomach as fast as it should, causing stomach acid to back up into your esophagus.
• Smoking. Smoking weakens the LES, allowing stomach acids to back up into your esophagus.
• Asthma. The relationship between asthma and heartburn is unclear. Coughing and trouble breathing may change the pressure in the chest. Or acid that has refluxed into the esophagus can, through reflex action, trigger a spasm of the airway leading to wheezing or asthma.

This article was reviewed and updated June 2007.