Tums could worsen heartburn in several ways. The first is a side effect known as acid rebound. This occurs when the stomach produces more acid to compensate for the effect of an antacid medication, such as Tums.

Tums contain the active ingredient calcium carbonate, an alkaline substance. When it mixes with an acid, it raises the pH level, making the stomach’s contents less acidic. This reduces the pain of heartburn.

However, the stomach needs acid to digest food and prevent infections, so it may sometimes produce more acid to counteract the reduction in acidity. This could result in heartburn coming back or even worsening.

The International Foundation for Gastrointestinal Disorders lists acid rebound as a potential side effect of taking calcium carbonate.

Another possibility is that the specific product a person is using contains other irritating ingredients, such as peppermint oil.

Some companies add peppermint oil to antacids to give them a minty flavor. However, mint, similar to spicy food, can be a triggerTrusted Source for some people with persistent acid reflux.

In some cases, antacids may also maskTrusted Source another underlying condition responsible for the heartburn. For example, peptic or gastric ulcers can cause heartburn. Antacids may ease the symptoms temporarily, but not forever.

To treat these underlying conditions, a person may need different medications or, in some cases, surgery to allow the condition to resolve.

If a person is experiencing worsening symptoms while taking antacids and is unsure why, they can try:

  • taking no more than the recommended maximum dose, as high doses may be more likely to cause acid rebound
  • taking antacids when acid levels are highest, such as after meals or before sleep
  • avoiding products with mint flavoring

If this does not help or the symptoms get significantly worse despite measures to help, a person can speak with a doctor.

Some signs that there may be an underlying condition include:

  • blood in the stool, which may look tarry or black
  • coughing or wheezing
  • difficulty swallowing
  • unexplained fatigue
  • pale or clammy skin
  • bloating

Seek emergency medical attention if a person develops heartburn alongside:

  • shortness of breath
  • sweating
  • nausea and vomiting
  • chest pressure, squeezing, or tightness
  • pain in the jaw, neck, shoulders, arms, back, or abdomen
  • lightheadedness or dizziness
  • confusion or weakness
  • loss of consciousness