The stomach as most of us are aware of is an important organ of the digestive tract and houses really concentrated stomach acid- hydrochloric acid. With a pH as low as 2, this acid is quite potent in causing a burning sensation in your chest and throat, giving this condition called Gastroesophageal Reflux Disease (GERD), its common name of heartburn! So, if this acid is so potent, what is the body’s mechanism of preventing it from refluxing in a normal condition? The lower end of the esophagus has a sphincter (LES) that prevents it from regurgitating the acidic food, chyme into the throat. In the diseased condition, the LES becomes kind of flaccid and lets this upward movement possible frequently.