There are physiological and pathological causes of chest tightness and shortness of breath in late pregnancy. Physiological causes generally do not affect the fetus, while pathological causes such as anemia and heart disease will have a certain effect on the fetus. 1. Physiological causes, late pregnancy due to uterine enlargement, the uterine floor rises, will produce pressure on the thoracic cavity, resulting in a reduction in the volume of the thorax, so pregnant women can appear chest tightness and shortness of breath manifestations, twin fetus is more obvious, but physiological phenomena do not affect the fetus, near full-term fetus into the basin after the symptoms will improve. 2. Pathological causes (1) Iron deficiency anemia, maternal hemoglobin and erythrocytes are reduced, oxygen carrying capacity is reduced, and dyspnea, chest tightness and shortness of breath may also occur. Mild anemia has little effect on the fetus, while moderate to severe anemia has insufficient oxygen and nutrients through the placenta to meet the growth requirements of the fetus, and may result in fetal growth restriction, intrauterine distress, and preterm delivery. (2) Heart disease, the mother suffers from heart disease, such as cardiomyopathy, rheumatic heart disease, etc., shortness of breath, panic, chest tightness and other manifestations can occur during pregnancy. In late pregnancy, due to the increased burden on the heart, the heart function will further deteriorate, which in turn will cause insufficient blood and oxygen supply to the placenta, and preterm labor, fetal growth restriction, fetal distress, neonatal asphyxia and other conditions may occur. Chest tightness and shortness of breath in late pregnancy should be checked in time, if it is a physiological phenomenon regular review can be, usually should count the fetal movement; if it is a pathological factor, according to the different causes of the disease under the guidance of the doctor for treatment.