It occurs when stomach acid splashes up into the esophagus. If left untended, acid reflux can cause changes to the lining of the esophagus and even lead to cancer.
Some people have it occasionally, while others experience it daily. It is the latter group of people who need to be most aware of what acid reflux means for their long-term health.
People who have it once a month don't need to worry, but those who have it once a week need to be concerned, said Dr. Amit Trehan, a gastroenterologist in private practice.
"It's important for most patients to realize it could a life-threatening problem," he said.
Treatment usually starts with lifestyle and dietary changes, Trehan said.
He listed foods that people with acid reflux should avoid or eat in limited quantities: peppermint, tomatoes, onions, carbonated drinks, chocolate, citrus products and alcohol.
These foods, plus tobacco, cause the muscle that separates the esophagus from the stomach to relax and let acid enter the esophagus, Trehan said.
Fried and high-fat foods are slow to empty out of the stomach and may rise up into the esophagus, he said.
Besides dietary changes, Trehan suggests people lose weight.
"It (extra pounds) definitely makes reflux worse," he said.
Also, eat smaller meals more frequently, don't wear tight belts, exercise regularly, don't eat right before bedtime or snack in bed, Trehan said.
Some patients, typically young people who respond to medication, are classic candidates for surgery to repair the valve between the food pipe and stomach, he said.
While occasional heartburn is normal, if someone experiences it six to eight weeks, he should see a physician, Trehan said.
Men 50 and older who develop acid reflux are at high risk for Barrett's esophagus.
When someone has Barrett's esophagus, that means the cells of the esophagus have changed to become like the lining of the small intestine, Trehan said.
"It's precancerous," he said.
Typical diagnosis is through endoscopy with a biopsy or capsule endoscopy without a biopsy, Trehan said.
People with acid reflux can also develop strictures, which means the lower part of the food pipe narrows, he said.
Children can also be at risk for acid reflux, Trehan said.
Some signs parents should note are ear infections, pain and vomiting, he said.
In adults, people may experience pains that are not like typical heartburn. They may have chest pains, a hoarse voice and nighttime cough, he said.