Heartburn Causes

While there are many heartburn causes, the important thing to remember is that at a base level, heartburn is caused by the contents of the stomach (particularly stomach acid) are moving up the esophagus and occasionally into the throat.

What Causes Heartburn?

A lot of things can trigger heartburn, but the primary cause of heartburn is a faulty lower esophageal sphincter (LES). This muscle is supposed to be contracted tightly in order to keep the stomach’s contents sealed.

Under normal conditions, the LES is a one-way valve, letting food and liquid into the stomach but not allowing anything to escape. However, with heartburn, this is not the case. While a lot of things contribute to heartburn, poor LES function is what causes heartburn.

A Faulty LES

The real question is.. why does the LES not fully contract and allow contents to escape? There seems to be a few factors which are the root heartburn causes:

  • Too much food in the stomach. Overeating causes the actual organ of the stomach to stretch significantly, which can give the LES problems sealing off. One way to reduce heartburn is to simply eat smaller meals.
  • Hiatal hernia: The diaphragm normally forms a roof over top of the abdomen, but sometimes a small tear forms in the hernia. The stomach then moves through this hole and is pressured by the diaphragm. This is a common cause of heartburn.
  • Pregnancy and Obesity: Carrying a baby (or simply a lot of extra visceral fat) puts pressure on all of the viscera, including the stomach. This can interfere with the function of the LES and this pressure is one of the most common heartburn causes. Pregnant women and obese people are much more likely to experience heartburn than the average person. Weight loss will significantly reduce the occurrence of heartburn, but unfortunately as many as half of pregnant women will experience heartburn (try out our top 2 heartburn remedies).
  • Alcohol consumption: Alcohol is an extreme irritant to the stomach. Nearly all alcoholics end up with a GERD diagnosis and even recreational drinking can be what causes heartburn.
  • Hypothyroidism: While this link is often not mentioned, an under-performing thyroid is associated with acid reflux (1). This link is likely passed over frequently because it was first shown in peer-reviewed research back in 1982. Hypothyroidism and GERD not very common conditions like they are today back in 1982 as obesity rates were much lower during that point in time.
  • Side effect of medication: Many medicines have the side effect of inducing heartburn. If you suddenly start experiencing heartburn after taking a new medication, consult with your doctor to discuss this issue. Perhaps you can find an alternative medication without the side effects or find another way to manage your heartburn.

Other Contributing Heartburn Causes

While the major heartburn causes have been listed above, some people get heartburn without any of those factors. Here is a list of secondary factors which can be causes of heartburn or increase its intensity:

  • Flat or declining bed: Gravity helps keep the contents of stomach where they belong. Laying completely flat or even at a slight decline (common due to certain bodyweight distributions, bed padding, and the shape of a mattress) can heighten heartburn. This can easily be corrected by lifting the end of the bed where the head lies. Note that this refers to the position of the stomach relative to the chest, not the head. Propping your head up on a pillow is not enough to relieve heartburn.
  • Stimulant usage: Coffee and Nicotine (found in cigarettes and other tobacco products) can stimulate acid production in the stomach and can both be heartburn causes.
  • Ulcers: Peptic ulcers can be a cause of heartburn (and can also be confused for heartburn).
  • Trigger Foods: Certain foods trigger heartburn in different people. Everyone is different, so you will have to experiment to see what does and does not give you heartburn. Fatty foods, spicy foods, and alcohol tend to be the biggest causes of heartburn.
  • Genetic Predisposition or unknown factor: Due to certain genetic and unknown factors, a very small portion of the population may be predisposed to heartburn due to excess acid production and faulty LES function.

Causes of Heartburn Conclusion

As you can see, there are a lot of heartburn causes. Just because you have many of the risk factors does not mean you have to be predisposed to a life of heartburn. Try out these two natural heartburn remedies for short term relief. For the long term, look to avoid trigger foods, elevate the head of your bed, and lose weight as these three things will significantly reduce your run-ins with heartburn in the future!


1. Eastwood GL, Braverman LE, White EM, Vander Salm TJ. Reversal of lower esophageal sphincter hypotension and esophageal aperistalsis after treatment for hypothyroidism. J Clin Gastroenterol. 1982 Aug;4(4):307-10.