Pregnant women feel chest tightness and shortness of breath, is a more common phenomenon during pregnancy, generally caused by lack of oxygen, may be caused by normal physiological reasons during pregnancy, may also be related to some diseases, need to be cautiously judged after the treatment of the cause. A, physiological reasons: 1, the uterus compression of lung tissue: after pregnancy, the volume of the uterus continues to increase, will gradually push to the abdominal cavity, the pressure of the abdominal cavity gradually increased, resulting in the diaphragm moved up, the volume of the thoracic cavity will be reduced, the lung tissue is restricted to a certain extent, so pregnant women will appear chest tightness and shortness of breath symptoms, especially when seen in the activity. The situation is a normal physiological phenomenon, and most of the symptoms are transient, a little rest can be recovered, no need to worry; 2, fetal growth needs: after pregnancy, with the growing fetus, the demand for oxygen and nutrition gradually increased, need more nutrition and oxygen, will make the mother’s cardiac output gradually increased, the heart and lung burden gradually increased, will also lead to pregnant women feel chest tightness, shortness of breath. Second, pathological reasons: for example, the existence of bronchial asthma in pregnant women, can make the lung function in a certain degree of decline, when the demand for oxygen increases after pregnancy, more than the compensatory degree of lung function, there will be chest tightness, shortness of breath symptoms, other common and hypoglycemia, ventricular septal defect, cardiac insufficiency and other diseases. Chest tightness and shortness of breath caused by disease factors are usually longer and should be promptly sought and actively treated.