"The glottis (middle of larynx) expands to allow more air in during the preparation for fight or flight." It has something to do with muscle tension and the glottis. The first theory is that when you try to swallow (a process that requires closing the glottis) against that expanded glottis, you're creating muscle tension, and thus discomfort. Theory number two is that the lump mainly occurs when "you're trying not to cry, which means you're trying to constrict the muscles in your throat while your glottis is trying to expand". Here's the traditional festive ad for British department store chain John Lewis...Herald app users tap here for today's video.

Source: New Zealand Herald November 10, 2016 16:07 UTC