Narrowing of the esophagus, or esophageal stricture, is not a cause of excess mucus in the throat, though it can be a cause of coughing, according to the Oral Cancer Foundation. Other symptoms of esophageal stricture are swallowing that is difficult or painful, explains MedlinePlus.
A person with esophageal stricute can also lose weight without meaning to, and can regurgitate his food.
Narrowing of the esophagus can be the result of a benign or malignant process, according to the Oral Cancer Foundation. It is caused by acid reflux, irritants, injury and esophageal cancer, all of which cause scar tissue in the esophagus and cause it to narrow. It can even be the result of pills that are stuck in the esophagus.