Why Heartburn Happens

Why Does Heartburn Occur and What Causes It?

Home-made chili can cause heartburn
Why does heartburn happen for some people but not for others?. Louise LeGresley/Moment Open/Getty Images

You've likely complained about heartburn at some time in the past, or at least heard someone else mention this symptom. What causes heartburn to occur, both causes and mechanisms? Why do some people experience heartburn and others not? What is the difference between "functional" heartburn and GERD?

Heartburn is Common

Heartburn is that burning sensation in the middle of your chest you can get after a meal.

It's a common condition affecting more than 40 percent of all Americans (approximately 108 million people) at least once a month.

Not everyone, however, suffers from heartburn, even when they eat spicy foods. For millions of people, however, heartburn can be a sign of a chronic condition such as GERD?

Heartburn, Acid Reflux or GERD?

Anyone can have occasional heartburn, such as after eating a spicy meal. You can manage this type of heartburn (non-erosive reflux disease) fairly easily through lifestyle changes and perhaps an antacid. Frequent and recurring heartburn, however, may be a symptom of a more serious condition: gastroesophageal reflux disease or GERD.

GERD is a disease in which acid from the stomach flows back (or "refluxes") into the esophagus, which can cause irritation and damage to the lining of the esophagus. Some degree of acid reflux is normal, and typically occurs after meals.

Episodes are usually brief, and cause no symptoms. Frequent symptoms, such as heartburn and regurgitation, are an indication that potential injury to tissues has occurred from longer and more frequent acid exposure than normal. In general, damage occurs because of the following reasons: stomach contents are refluxed too frequently, the contents of the stomach are too acidic, or the contents cannot be cleared from the esophagus fast enough.

What Causes Heartburn?

Heartburn can occur for a number of reasons. These include what you eat, some medications you may take, and lifestyle habits you have. Being aware of what the triggers can be will help you with controlling the heartburn.

Heartburn and What You Eat

There are certain foods that can worsen heartburn symptoms. Some foods can weaken the lower esophageal sphincter (LES), allowing stomach contents to flow up into the esophagus, while other foods will increase the production of stomach acid. The foods that most often trigger heartburn are fried, fatty, or spicy foods. There are other foods heartburn sufferers should avoid, along with foods that are safe for most heartburn sufferers.

Heartburn and Medications

It isn't just food that can cause heartburn. Sometimes it's the medications we take to treat other conditions that can be the culprit. Some medications can cause heartburn by relaxing the LES, allowing stomach contents to reflux back up into the esophagus. Some of these include some of the medications used for the treatment of asthma, chronic pain, antidepressants, and heart-related conditions. You can read this list of medications that can trigger heartburn.

Heartburn and Lifestyle Habits

The chances of heartburn occurring can increase because of our lifestyle habits—what we do and how we do it.

Heartburn symptoms can often be relieved if sufferers make a few lifestyle changes. These include when we eat, when and how we sleep, and what daily activities should be avoided. Check out this list of lifestyle changes for heartburn prevention to see if there is anything you can do yourself to lessen your heartburn.

Mechanisms Leading to Heartburn

There are several mechanisms that can lead to heartburn, and often a combination of these is responsible. These include:

  • Foods and medications which irritate the esophagus directly.
  • Lower esophageal sphincter dysfunction (LES) - The lower esophageal sphincter functions is a "gate" between the lower esophagus and the stomach. If this sphincter does not shut and stay shut properly, the acid content of the stomach can push back up into the esophagus causing irritation. There are many conditions which can result in weakening of the LES, some medications can weaken the LES, and excessive abdominal pressure (for example, due to pregnancy or obesity) can lead to reflux through this gate.
  • Motility disorders - The muscles and nerves surrounding the stomach are very important in their role of continually moving foods through the digestive tract. A lack of motility can be caused by medical conditions or medications which interfere with the nerves. When food doesn't move through the stomach readily (with delayed gastric emptying), pressure builds up in the stomach and contents (including acid) can reflux back up into the esophagus.

Medical Conditions Causing Heartburn

There are several medical conditions, including GERD, where heartburn can be a symptom. These include:

  • GERD - GERD is a common condition in which the contents of the esophagus flow backward into the esophagus causing irritation. When the condition becomes chronic it can lead to precancerous changes in the esophagus (Barrett's esophagus) and even esophageal cancer.
  • Hiatal hernias - Hiatal hernias occur when the stomach slips backwards into the chest cavity through the opening in the diaphragm. This, especially when combined with reduced lower esophageal sphincter contraction, can result in reflux of acid into the esophagus.
  • Peptic ulcers - With peptic ulcers, the acid in the stomach leads to erosion and ulceration (thus the term ulcers) of the stomach lining.
  • Gastroparesis - Gastroparesis, or damage to the nerves going to the stomach resulting in slower gastric emptying, is most common in people with long-standing diabetes.
  • Achalasia is a motility disorder in which the nerves traveling to the esophagus are damaged. Achalasia can easily be misdiagnosed as GERD. Since the LES does not close properly (due to this nerve damage), acid can return to the esophagus.


Kasper, Dennis L., Anthony S. Fauci, Stephen L. Hauser, Dan L. Longo, J. Larry Jameson, and Joseph Loscalzo. Harrison's Principles of Internal Medicine. New York: McGraw Hill Education, 2015. Print.

Weijenborg, P., Smout, A., and A. Bredenoord. Esophageal Acid Sensitivity and Mucosal Integrity in Patients with Functional Heartburn. Neurogastroenterology and Motility. 2016. 28(11):1649-1654.

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