Frequent and recurring heartburn may be a symptom of a more serious condition called Gastroesophageal Reflux Disease, or GERD. GERD occurs when acid from the stomach flows back (or "refluxes") into the esophagus, which can cause irritation and damage to the lining of the esophagus.

Normally when you eat and drink, the muscle at the bottom of your esophagus closes off so food and liquids will remain in your stomach. Most cases of acid reflux are responsible because of a dysfunction in the esophageal sphincter muscle, esophageal contractions, or the process of emptying the stomach.

For some people, acid reflux is normal, and briefly occurs after eating meals but causes no symptoms.  Frequent symptoms, such as heartburn and regurgitation are  signs that there is potential injury to the esophagus tissue.  

Acid reflux or GERD occurs because of the following reasons:

- stomach contents are refluxed too frequently
- the esophagus's normal defenses are overwhelmed by the acid content of the stomach,
- the body produces an abnormal excess of stomach acid
- the contents of the stomach are too acidic,
- or that the food is not cleared from the esophagus fast enough
- hormone imbalances

When "refluxed" stomach acid touches the lining of the esophagus, it causes a burning sensation in the chest or throat called heartburn. The fluid may even reach the back of the mouth, and this is called acid indigestion. Occasional heartburn is common but does not necessarily mean one has GERD. Heartburn that occurs more than twice a week may be considered GERD, and it can eventually lead to more serious health problems.

Other symptoms of acid reflux can include:

* Pain in the chest
* Hoarseness in the morning
* Trouble swallowing
* May feel like food is stuck in the throat
* Choking sensation
* Persistent dry cough
* Bad breath

The causes or causes of acid reflux can vary from case to case, or even within a single case over time. Diagnostic tests can often help you determine the root of your symptoms so you can establish the best treatment plan for your individual circumstances.