The term itself has been used only a decade or two. But the disease has been around as long as heartburn. A National Institutes of Health publication cited by the National Digestive Diseases Information Clearinghouse puts the number of sufferers at 3 percent to 7 percent of the U.S. population -- as many as 20 million people.

"GERD occurs when the acidic contents of the stomach flow back into the esophagus and irritates or damages the tissue," said Connie Crawley, an Extension Service nutrition and health specialist with the University of Georgia College of Family and Consumer Sciences.

GERD Basics

The esophagus is the tube that connects the throat to the stomach. Usually, the stomach contents are kept from going back up this tube by a sphincter, or a muscular ring that opens and closes as we swallow food.

"When a person has GERD," Crawley said, "this sphincter doesn't close tightly, allowing the stomach contents to go back up into the esophagus."

That backflow happens to a slight extent in virtually everybody. But for many, the reflux is severe. Over time, the repeated flow of acids damages the lining of the esophagus.

The most common symptoms are:

• Heartburn, an uncomfortable, rising, burning sensation behind the breastbone.
• Regurgitation of gastric acid or sour contents into the mouth.
• Difficult and/or painful swallowing.
• Chest pain.

Overeating can make the symptoms worse, Crawley said. So can smoking, drinking alcohol or being pregnant or overweight, or even wearing tight clothes.

Caffeine makes it worse, too, as do chocolate, fruits, juices, tomatoes, peppermint and fatty foods.

"Fats stay in the stomach longer," Crawley said. "Carbohydrates are the first thing out of the stomach, then proteins. High-fat meals are digested more slowly, and fat seems to make the sphincter looser and more likely to open. So GERD symptoms may be worse after high-fat meals."

The Best Advice

The most important advice Crawley has for people with GERD symptoms is to see a doctor, especially if symptoms are getting worse or don't improve with lifestyle changes.

"If the problem isn't treated, the tissue of the esophagus can be worn away, leading to an ulcer and even a narrowing of the tube due to scar tissue," she said. "This narrowing makes it hard for the person to eat and requires surgery for repair. The reflux can even go into the lungs, leading to pneumonia."

For now, there is no cure for GERD.

"But it can be managed with medication and lifestyle changes," Crawley said.

Managing GERD

Among the helpful things suffers can do:

• Sleep with your head elevated 6 inches.
• Don't eat for at least two hours before bed.
• Don't smoke.
• Avoid food and drink that cause symptoms.
• Keep meals and snacks small.
• Lose weight if you're overweight.