Dyspnea in late pregnancy may be physiological because in late pregnancy the fetus gradually increases in size and lifts upward to compress the diaphragm, causing the chest cavity to become smaller and causing the breathing of the lungs to be affected. At the same time, the body load of women in late pregnancy increases, and the heart load increases with it, so there will be symptoms of dyspnea. Pregnant women are advised to lie properly on their left side and breathe fresh air, which can relieve dyspnea to some extent. If it still can’t be relieved, go to the hospital in time, the following pathological factors may exist: 1. Pulmonary embolism: the blood is in a hypercoagulable state during pregnancy, and the increase in blood volume and pelvic and abdominal pressure are important factors for thrombosis, and the main manifestations of pulmonary embolism are breathing difficulty, chest pain, chest tightness and increased heart rate. It is recommended to go to the respiratory department for relevant examinations, including blood routine, coagulation function, D-dimer, etc., and CT examination of the lung if necessary. Heparin is the main therapeutic drug and should be applied intravenously in case of emergency. 2. Chronic obstructive pulmonary disease (COPD): It can also cause dyspnea in late pregnancy. Shortness of breath or dyspnea is the main symptom of COPD, accompanied by wheezing, chest tightness, coughing and coughing. If necessary, give oxygen therapy, eat more fruits and vegetables daily, and use bronchodilators, glucocorticoids and other drugs as prescribed by the doctor; 3. Perinatal cardiomyopathy: refers to cardiac lesions occurring in the last month of pregnancy until 5 months after delivery, with no previous history of cardiovascular system diseases, mainly manifesting as acute heart failure, such as dyspnea, double lung auscultation full of wet rales, etc. It is recommended to do ECG, cardiac ultrasound and cardiac function tests immediately, and in serious cases, early cesarean section is needed to terminate the pregnancy; 4. Congenital heart disease: when pregnant women have congenital heart disease combined, dyspnea can also occur due to overload of the heart. It is necessary to strengthen the detection and terminate the pregnancy if necessary to ensure the safety of mother and child. Therefore, in late pregnancy, pregnant women should receive regular checkups, perform proper exercise and reasonable diet, and provide necessary psychological guidance to relieve anxiety.