1, in the early stages of pregnancy, due to pregnancy, the whole body of the pregnant woman to varying degrees of physiological changes, the body can not adapt, there will be a variety of symptoms, dizziness and blurred vision is one of them. If it occurs in early pregnancy, there are no adverse consequences. (1) When the vegetative nervous system of pregnant women is out of order and the motor nerves that regulate blood vessels are unstable, dizziness may occur due to transient cerebral ischemia when there is a sudden change in body position. (2) Low food intake caused by pregnancy reaction is often accompanied by low blood sugar, thus making it easy for dizziness and dizziness to occur. It is especially easy to happen when standing up suddenly, standing for a long time, bathing in the shower hall, or in crowded flow of people. Once it happens, you should squat down immediately, or lie down and rest for a while. If this phenomenon occurs frequently, there is a possibility of anemia, low or high blood pressure, malnutrition or heart disease, and you should seek medical examination in time. 2, in the middle and late stages of pregnancy, the main cause is anemia. After pregnancy, in order to adapt to the growth needs of the fetus, pregnant women’s blood volume increases, the blood is relatively diluted, the formation of physiological anemia, at this time should be regularly check the blood routine, such as anemia is serious, then you need to take oral anti-anemia drugs to be corrected. Dizziness occurs in the mid-pregnancy is due to the placenta of the arteries and veins to form a short circuit between the peripheral vascular dilatation resistance decreases, so that the diastolic blood pressure of pregnant women lower than before pregnancy, as well as the entire pelvic range of blood vessels during pregnancy, a significant increase in the high degree of expansion of blood, so that the blood is more concentrated in the uterus of the lower abdomen, coupled with the increasing uterus and compression of the vena cava of the inferior vena cava reflux, so that the return of blood to the heart to reduce the amount of cardiac excretion decreased, resulting in a decrease in cardiac excretion, causing Low blood pressure and temporary cerebral ischemia.