Heartburn is AQCANone of the most common ailments people deal with regularly. According to a National Institutes of Health report, about 60 million Americans experience heartburn at least once a month, while some 15 million feel some measure of it daily. 

Though its name suggests an issue with one's heart, heartburn is actually a symptom of acid reflux − the burning sensation of acid refluxing up from one's stomach and into the esophagus. While several conditions contribute to heartburn, one of its most commonly recommended treatments is Alka-Seltzer − an antacid known for "decreasing the amount of acid in the stomach," says Lisa Young, PhD, RDN, an adjunct professor of nutrition at New York University and author of "Finally Full, Finally Slim."

What is Alka-Seltzer?

In addition to decreasing one's amount of stomach acid, the over-the-counter medication also "helps to buffer or neutralize stomach acid," says Jamie Bering, MD, a gastroenterologist at Mayo Clinic in Arizona.

Each Alka-Seltzer tablet dissolves quickly in water and contains three active ingredients. These include: 

• Aspirin - known for its minor pain-relieving, anti-inflammatory, and fever-reducing effects. 
• Sodium bicarbonate or baking soda - "which is what helps neutralize stomach acid," says Jen Messer, a nutrition consultant and registered dietitian at Jen Messer Nutrition.
• Citric acid - important because it "reacts with water and the sodium bicarbonate to give the effervescence or fizzy effect," Messer explains.

What does Alka-Seltzer do?

While each ingredient provides these individual benefits, the three-part combination of the medication is what makes Alka-Seltzer ideal for "relieving symptoms of heartburn or indigestion," says Bering.

In addition to its usefulness against heartburn, Alka-Seltzer is also marketed to provide relief for a number of other conditions and ailments. These include "everything from minor aches and pains to fever, inflammation and even hangovers," says Messer.  

When should you not use Alka-Seltzer?

Despite its usefulness with some such conditions or symptoms, Alka-Seltzer is not for everyone. Though rare, the antacid can cause a severe allergic reaction in some users. Individuals who experience hives, wheezing or face swelling after taking Alka-Seltzer should seek the care of a physician right away. 

The Food and Drug Administration (FDA) also advises against pregnant women taking nonsteroidal anti-inflammatory drugs (NSAIDs) at 20 weeks or later of pregnancy, which would include Alka-Seltzer because the aspirin found therein is a type of NSAID. NSAIDs taken during pregnancy can cause rare but serious kidney problems in fetuses and can lead to low levels of amniotic fluid, per Mayo Clinic. Alka-Seltzer should also not be taken by anyone taking any other type of NSAID. These include other medications containing aspirin, plus ibuprofen, naproxen and Celebrex. 

It's also important to note that even when taken as directed, "Alka-Seltzer may provide only temporary relief" against certain conditions or symptoms, says Messer. "If symptoms persist or worsen after taking it," she suggests, "it's advisable to seek medical attention." 

What to know to stay safe:Popular heartburn medicine may increase dementia risk by 33%.