system
Given the following post, respond as if you're commenting on Reddit:
human
ELi5: what is that horrible painful massive 'lump' in your chest when you drink or eat something too fast?
gpt
Food and fluids get transported through your esophagus. Where the esophagus connnects to the stomach, a) it has to pass through an ligamentous opening in the diaphragm, which is a rather narrow passage and b) there is a sphincter muscle that is usually contracted to prevent stomach acid to flow back into the esophagus. When you swallow your food too quickly, the sphincter may need a few extra seconds to relax and let the food into the stomach. In these - usually - seconds, the food is stuck in the esophagus, which is unfortunately located right behind the heart. And your heart really dislikes something pressing against it, therefore causing that uncomfortable feeling.