Women in the third trimester of pregnancy suddenly dizziness, mainly consider the following aspects of the cause: 1, may be malnutrition caused by anemia, generally in the first trimester of pregnancy may be heavy early pregnancy reaction, patients usually do not eat well, always have nausea, vomiting will cause patients anemia; 2, patients in the third trimester of pregnancy suddenly dizziness, but also to consider may be caused by increased blood pressure, it is recommended that the blood pressure It is recommended to check the blood pressure to clarify. If the blood pressure is high, timely intervention should be carried out to avoid causing images to the pregnant woman and the fetus; 3, sudden dizziness in the third trimester of pregnancy may also be an attack of peripheral vertigo, such as dizziness during the change of head position should be considered as otoliths, while if the patient is dizzy, accompanied by tinnitus, ear congestion and hearing loss, it should be considered as caused by Meniere’s disease.