The chest tightness after eating betel nut for the first time is because betel nut contains betel nut alkaloids. The role of betel nut alkaloids is to excite choline receptors, causing increased glandular secretion, can also increase intestinal peristalsis, constriction of the bronchial tubes, thus causing vasodilation, chest tightness symptoms, some people may also have a serious drop in blood pressure. If you have chest tightness, you should immediately stop eating betel nut, and mild symptoms can wait 5 to 10 minutes to subside on their own. In addition, you should also drink a lot of water, can dilute betel nut alkali.