GERD (acid reflux) is a possibility -- the acid can irritate your esophagus, and sometimes your body reacts by producing extra mucus to protect the esophagus.
You may want to test this theory by trying a med like Prilosec and/or avoiding common GERD trigger foods, such as caffeine, soda, alcohol, chocolate, acidic foods (citrus, tomatoes, pineapple, etc.), garlic, onions, spicy food, deep-fried or fatty foods, and mint.... Triggers can vary from person to person but that's a good starting list. A doctor can also perform an endoscopy to look for damage in the esophagus and stomach, but most doctors diagnose GERD by trying meds and/or diet, and if it works, then you must have had GERD :)
(I have GERD so this comes to mind!)
Post Edited (girl_geek) : 9/13/2012 8:33:06 AM (GMT-6)