It is not nitroglycerin, but is a proprietary Chinese medicine, consisting of Chuanxiong and ice chips, Chuanxiong has the effect of moving qi and blood, and ice chips are aromatic and open the orifice. Nitroglycerin is a western medicine of nitrate ester, which can directly relax vascular smooth muscle, especially small blood vessel smooth muscle, which can dilate peripheral blood vessels, reduce peripheral resistance, decrease the amount of return blood, reduce cardiac output, reduce cardiac load, reduce myocardial oxygen consumption, and thus get relief from angina pectoris. In addition, nitroglycerin can also promote the formation of collateral circulation, and the effect is rapid after sublingual administration and can be maintained for 30 minutes. It also has a relaxing effect on other smooth muscles, and can appropriately relieve biliary colic, pyloric spasm and renal colic, but the duration of action is relatively short.