The aging body beholds one surprise after another. For example, did you know that your ears look bigger as you get older? Another of the not-so fun changes that can happen as we get older is being more prone to heartburn. You may find that certain meals you used to have no problem with — like pizza or a spicy curry — now mean having to knock back an antacid after you eat.

While anyone can get heartburn no matter how old they are, it’s more common with age. According to gastroenterologists, there are three main reasons for this. If heartburn is something you’re dealing with regularly, knowing the reason why is the first step to experiencing it less often. Knowing the root cause as well as some doctor-recommended tips for what to do when it happens can make heartburn a lot less likely.

What Exactly Is Heartburn, Anyway?

Before getting into how to avoid heartburn, it’s helpful to know what is actually happening in the body to cause it. “Heartburn happens when stomach acid moves up into the esophagus, the tube that connects your mouth to your stomach,” said Dr. Vivek Lal, a microbiome scientist and founder of Resbiotic. He explained that this usually occurs when the lower esophageal sphincter, a ring of muscle that acts like a valve, relaxes or is weakened.