The vast majority of women begin to experience some of the corresponding symptoms when they are about 45 days pregnant, mainly due to the increase in estrogen in the body, which is why it leads to nausea, vomiting, anorexia, or clinical manifestations such as fatigue and drowsiness. With the further progression of pregnancy, these symptoms will be reduced around the tenth week of pregnancy. If you suddenly have a general lack of strength in the third month of pregnancy, you must do the following tests to rule out the possibility of some diseases: 1. Do routine blood tests to find out whether there are symptoms of anemia. 2. It is recommended to do liver and kidney function tests to find out whether liver and kidney functions are normal at this time, and to rule out the possibility of other diseases through laboratory tests. In addition, we also need to know whether the diet in daily life is normal or not, if the nutrition can not keep up with the situation, there will also be a general lack of strength, after the examination according to the results and then give appropriate treatment.