webMD說胃酸反流會讓鼻水積在嗓子裏流不下去，感覺像鼻水倒流

http://www.webmd.com/allergies/postnasal-drip

Sometimes the problem is not that you're producing too much mucus, but rather that it's not being cleared away effectively. Swallowing problems can cause a buildup of liquids in the throat, which can feel like postnasal drip. These problems can sometimes occur with age, a blockage, or conditions such as gastroesophageal reflux disease (GERD).