Pregnant women in the 3rd trimester are in early pregnancy and chest tightness is a common symptom of early pregnancy reaction, mainly related to the elevated HCG value and progesterone in early pregnancy, which causes stimulation to the organism resulting in chest tightness. In addition, symptoms such as nausea, vomiting, drowsiness and lack of concentration may also occur. Mild symptoms usually do not require special treatment and can gradually reduce on their own until they disappear. But in addition, you need to be alert to other diseases that cause: 1, cardiovascular disease: such as pregnant women suffering from cardiovascular disease, the heart blood supply and oxygen supply increase during pregnancy, the burden on the heart gradually increases, which can affect the oxygen supply, thus leading to chest tightness, serum myocardial enzymology, electrocardiogram, cardiac ultrasound and other tests need to be performed, if necessary, perform dynamic electrocardiogram to exclude arrhythmias, find out the cause and make targeted treatment; 2, Respiratory diseases: for example, during upper respiratory tract infection, pregnant women can also have chest tightness, accompanied by sneezing, runny nose, coughing symptoms, usually with obvious triggering factors, such as rain, cold, sudden changes in climate, etc.; 3, other factors: in the process of pregnancy, some pregnant women, especially primiparous women do not adapt well, in the case of fatigue or excessive tension, anxiety will appear chest tightness, relaxation and rest can more Relief. With the gradual increase in the size of the uterus, it will also compress the chest, which will reduce the volume of the thorax and interfere with normal breathing and aggravate chest tightness. When chest tightness occurs, timely examination should be carried out to exclude disease factors, ensure sufficient rest and adjust the mood on a daily basis for the benefit of pregnancy health care.