Acid reflux isn’t just for adults. More than half of all newborns experience the condition within the first three months of life.

“If you look at the research available, 60-70 percent of infants will have significant reflux episodes,” said Dr. Steven Schwarz, a professor of pediatrics at SUNY Downstate Medical Center and attending pediatrician at Long Island College Hospital.

Acid reflux is caused by a back-up of the contents of the stomach, including gastric acid, into the esophagus. But with infants, the contents of the stomach often reflux past the esophagus and out the mouth, resulting in regurgitation and vomiting or spitting up.

Infant Acid Reflux

“It has to do with development of the gastrointestinal tract in this age group,” Schwarz told FOXNews.com. “Normal gastrointestinal function is not achieved until several months of life, and that includes gastroesophageal function — so what happens is you have lower esophageal relaxation.”

Acid reflux in infants usually occurs right after feeding, but until the muscle between the esophagus and the stomach matures, it can occur anytime a baby coughs, cries or strains.

Generally, if spitting up is the only symptom, doctors recommend some simple feeding and lifestyle modifications, Schwarz said.

Some suggestions include:

— Decreasing feeding volumes if the baby is formula fed;

— Decreasing feeding times if the baby is breast fed;

— Thickening formula or, on occasion, switching to a hypoallergenic formula;

— Smaller, more frequent meals.

In most cases, infant acid reflux will clear up on its own by 8-10 months of age, but in some rare cases, babies can develop breathing problems and/or acid-induced injury to the esophagus, called esophagitis.

So it’s important for parents to know the signs and symptoms that could indicate a bigger problem, including:

— Failure to gain weight;

— Irritability during feeding;

— Refusal to feed;

— Presence of blood in spit up;

— Breathing problems.

“Pharmacologic therapy should be reserved for those infants who demonstrate signs or symptoms of a complicated problem,” said Schwarz. “There’s nothing parents can do to prevent it, and basically for the vast majority of infants with reflux — which is most infants — as long as the baby is thriving and happy, there is no reason for concern.”

Growing Up With GERD

While most infants will outgrow frequent episodes of acid reflux as their digestive system matures, a small percentage will not outgrow the condition, and these children are more likely to develop the chronic condition, gastroesophageal reflux disease, also known as GERD, during childhood.

“In most older kids who have symptomatic reflux, they probably had it as an infant and it just never resolved completely,” Schwarz told FOXNews.com. “But typically, symptoms after infancy may be delayed until the age of 3 or 4.”

For the 5-8 percent of adolescents who suffer from GERD, the condition caused by chronic reflux of stomach acid into the esophagus, symptoms are often similar to those experienced by adults living with the disease.

“The older you get, the less likely that vomiting becomes a primary symptom of reflux, so in older children and adolescents, it presents as acid coming up into the esophagus,” said Schwarz.

Common symptoms of childhood acid reflux include:

— Regurgitation;

— Heartburn;

— Abdominal pain;

— Hoarseness;

— Chest pain.

Although acid reflux is relatively common among adolescents, parents should know when to bring their child to the doctor, because prolonged exposure to acid in the esophagus as a child can cause problems like scarring and narrowing of the tube later in life, Schwarz warns.

“When a child complains of heartburn or pain just below the sternum, or when they start having pain in other locations, that’s a red flag,” he said.

Treating Kids With GERD

Much like their adult counterparts, children can also employ simple diet and lifestyle modifications to control their reflux-related symptoms.

“There are certain foods which we know are worse for patients with reflux,” Schwarz said. “Avoiding tomatoes, citrus products, caffeine, chocolate, and peppermint, can help, but lifestyle modifications should always be done under the care of a physician.”

Depending on the severity of the child's symptoms, doctors may try acid-suppression therapy using everything from over-the-counter antacids to prescription medications for a period of 6-8 weeks at a time. But the response to these therapies is varied, and sometimes patients become medication-dependent.

“Some patients are okay on the medication but as soon as you take them off, they become symptomatic again, and those patients may require surgery,” said Schwarz.

The Teen Years

As if being a teenager isn’t hard enough –- for kids living with acid reflux, these awkward years caught between adolescence and adulthood may bring even more than just typical teenaged angst.

Because we are an obese culture, we are seeing more and more cases of symptomatic reflux, Schwarz said.

So it’s extremely important for teens living with acid reflux or GERD to make healthy diet and lifestyle decisions.

Teenagers with acid reflux may want to try eating smaller, more frequent meals, avoid eating certain foods, and stay away from smoking and drinking alcohol.