Sudden chest tightness and fainting may be caused by low blood pressure, cerebral ischemia or high atrioventricular block, and different treatments can be taken according to different causes. 1. Low blood pressure: If low blood pressure is the cause of chest tightness and fainting, the first choice is to pay attention to rest, and promptly replenish saline or sugary drinks. If necessary, you can use norepinephrine, mesalamine and other drugs under the guidance of a doctor to raise blood pressure. 2. Cerebral ischemia: If cerebral ischemia is caused by high blood pressure, high blood fat, heart disease and other diseases, you can take anti-platelet aggregation drugs under the guidance of a doctor, such as Pansentin, aspirin, flunarizine hydrochloride and other drugs for treatment. 3. High atrioventricular block: High atrioventricular block can also cause sudden chest tightness and fainting, and patients with obvious symptoms can be treated with atropine and isoproterenol under the guidance of a doctor, and implantation of a pacemaker if necessary. There are many causes of sudden chest tightness and fainting, and it is recommended that patients go to the hospital in a timely manner to identify the cause of the disease and then actively carry out treatment.