Heartburn Causes

When you eat, food travels down your esophagus - or food pipe - and enters your stomach via the lower esophageal sphincter (LES), a ring of muscles that forms a valve.

Normally this is a one-way process. However, if this valve relaxes or doesn’t close completely, your stomach acid can flow the other way.

Unlike the stomach, the esophagus isn’t meant to house acid, so that’s why you feel the burn.

Though this process can be caused by a range of factors, food and beverages are the most common culprits. But why?

Your stomach may react to some foods or beverages by increasing acid production, slowing down digestion or relaxing the LES so that the acidic contents of your stomach leak back into your esophagus. 

Heartburn culprits

It’s the acid from your stomach irritating your esophagus. But what causes that? The short answer is: It varies with each person.

Despite the array of heartburn causes, they can be grouped into two simple categories: first, those that relax your lower esophageal sphincter (LES) – which makes it easy for the acid to get out (move up the esophagus)– and then those that make your digestive juices more acidic, meaning you feel the burn more.

This is true for both foods and beverages that cause heartburn, and other triggers related to your lifestyle.

Certain foods and beverages contain ingredients that are known to relax the LES, preventing it from properly tightening. For example, stimulants like the caffeine found in chocolate, coffee and tea relax the LES.

Foods and beverages that relax the LES

  • Chocolate
  • Coffee & tea
  • Peppermint
  • Garlic and onion
  • Fried or fatty foods


Acidic foods, and stress trigger your stomach to produce more acid. Tiredness can increase your perception of heartburn. More acid means more pressure in your stomach increases and the only way for it to go is up in your esophagus, resulting in heartburn. When you drink carbonated beverages, the gases they release also increases pressure on the LES, forcing it to open.

Being overweight puts external pressure on stomach contents, which in turn put pressure on the LES, forcing it to open. This creates an easy pathway for acid to reflux. Drinking alcohol and smoking relax your muscles, and this includes the LES. As we’ve learned, when the LES is relaxed acid can more easily reflux into your esophagus.

Identifying your heartburn causes would be simple if each trigger affected everyone in the same way. Spoiler alert: They don’t.

The key is to play detective and to try keeping a record of which out of the heartburn causes above could have triggered the burn.

The specific conditions of your own diet and lifestyle will play a part. Let’s look at two examples of everyday situations that could be affecting your heartburn.

Liz, 37 years old, administrative assistant*

Now that she has young children, Liz is becoming more careful with her habits. She wants to be a positive role model for a healthy lifestyle, but like everyone else, she can get derailed by stress. Liz looked more into what may be causing her heartburn and stress was a key trigger. Liz needs something that can help her prevent or relieve her symptoms associated with heartburn.

Bob, 41 years old, senior sales manager*

Bob is becoming more aware of his digestive health and has learned to identify the burning feeling in his chest as heartburn. But he doesn’t want to deprive himself of the food he loves—food is one of the greatest pleasures in life, after all! He suspects that being overweight is also a culprit, along with his favourite indulgences.

*Fictitious patients

Keeping a ‘heartburn diary’ could be the key to identifying what is causing your heartburn. The different factors can make it hard to isolate unless you’re keeping a record over time. Start by eliminating all known heartburn triggers from your diet and life.

Start adding one at a time back to your daily routine and make note if any seem to trigger your heartburn. Some people might only have one trigger, some might have many.

The good news is once you have worked out what is causing your heartburn, there are plenty of things you can do to remedy the situation. From heartburn treatments to diet changes and getting more exercise, you can do a lot to get relief from your symptoms.