Gastroesophageal Reflux Disease, or GERD, is a condition in which stomach acid backs up in a person's esophagus. Because the esophagus is not meant to handle corrosive substances, it causes a number of unpleasant symptoms. These can include heartburn, reflux of the stomach contents into the throat, nausea, vomiting, and thick phlegm in the throat. Eventually it can lead to coughing, asthma, inflammation of the throat, larynx, and lungs, and sinus problems.
According to Dr. Kurt Barrett, GERD can be the source of a number of symptoms that may not appear to be related to the digestive system. One of these is the excessive production of phlegm. This is actually one of the body's reactions to the acid that is invading the esophagus. Your body will try to neutralize the acid in a number of ways, trying to trap the stomach contents and neutralize or absorb them. One of these ways is the production of a sticky, gummy phlegm to coat the esophagus and protect it from the corrosive stomach acid. GERD sufferers often feel like they have something stuck in the back of their throats due to the thickness and adherence of this mucus.
The ongoing effects of GERD can lead to other problems, such as sinus trouble. Dr. Barrett says that a person can even unwittingly make the problems worse. For example, if you bend frequently, this allows the acidic stomach contents to move even higher into the throat. The body's phlegm production will increase to the point where it can cause what seems to be a sinus problem. However, when the GERD is treated, the sinus symptoms disappear.