Why do some people throw up when they eat spicy food?

Throw up, also called vomit, puke, and upchuck, is half-digested food and liquid that gets mixed up with your stomach juices and comes out of your mouth. Vomit happens when your stomach starts to feel queasy (or nauseated), sometimes after you exercise or run around too much after eating, eat too much food, or eat food that is spicy and therefore irritating to your stomach. Normally, your stomach processes your food well through the digestive system, but if you eat food with lots of bacteria or if you have a virus in your stomach, the quickest way for your body to get rid of the irritants is to vomit them out. Your brain tells the muscles in your stomach walls to spasm (contract abnormally); it also tells your diaphragm—the large sheet of muscles that separates your chest from your abdomen and is most responsible for your breathing—to press downward on your stomach. These activities combine to force the contents of your stomach up and out.