Clinically, nitroglycerin can be used to prevent angina pectoris, lower blood pressure and treat heart failure. The dose of nitroglycerin for angina pectoris is usually 1-2 tablets, and if 3 tablets or more are ineffective, prompt medical attention should be sought. At the same time, the use of nitroglycerin during prolonged squatting or exercise can prevent heart failure. It should be noted that there are many clinical subtypes of angina pectoris, and nitroglycerin has different effects on different types of angina pectoris, so patients should consult their doctor at the hospital.