Whether chest tightness at night at 33 weeks of twin pregnancy is normal or not should be decided according to the etiology, it may be a normal phenomenon due to twin pregnancy, or it may be caused by cardiac insufficiency, pneumonia and other pathological reasons. 1. Physiological phenomenon: at 33 weeks of twin pregnancy, the increasing uterus may compress the surrounding organs and restrict the thoracic activity, making the thoracic activity smaller, the pregnant woman will feel more difficult to breathe and chest tightness, which is a normal phenomenon, the pregnant woman can relieve the symptom by resting more, breathing fresh air and so on. 2. Pathological causes: pregnant women who are 33 weeks pregnant with two children and have chest tightness at night also need to pay attention to the presence of cardiac insufficiency, myocardial ischemia, arrhythmia, gastric ulcers, reflux esophagitis, bronchial asthma, COPD, etc., which can lead to chest tightness in pregnant women, and attention should be paid to the investigation. The 33 weeks pregnant with two babies at night chest tightness should be timely to go to the hospital, improve the examination, clear the cause of the disease and then give targeted treatment.