Gastroesophageal reflux disease, often known as GERD or chronic acid reflux, is a condition in the digestive system when a weak GI (gastrointestinal) tract with low muscle tone can allow the liquid content of the stomach to regurgitate (reverse or reflux) into the esophagus. The liquid can inflame and damage the delicate lining of the esophagus although visible signs of inflammation are infrequent.
Gravity, swallowing, and saliva are important protective mechanisms for the esophagus, but they are effective only when individuals are in the upright position and have good pharyngeal, gastro-intestinal and abdominal muscle tone. Muscles, including the smooth muscle of the GI tract, contract in response to nerve stimulation.
Greater stimulation means more contraction. Less stimulation means less contraction.


The muscles of the stomach can only function normally if they are receiving the correct information by the Vagus nerve. This nerve has its origins in the brain stem which is protected by the atlas and axis vertebrae. A deviation in the correct alignment of these vertebrae may result in an irritation of the Vagus nerve and potentially acid reflux and heartburn could be the result.