The first trimester is the most important stage in the development of the fetus, and during the first trimester pregnant women experience a series of uncomfortable symptoms. In general, symptoms such as dizziness do not occur in the early stages of pregnancy. However, in the following cases, pregnant women may experience dizziness: 1. Heavy early pregnancy reaction: When the early pregnancy reaction is heavy in the early stage of pregnancy, it can be manifested as nausea and vomiting, and in serious cases, they cannot eat and drink. If there is a serious early pregnancy reaction, but not timely consultation in the hospital, may lead to ion disorders and other conditions, and then pregnant women can feel dizzy symptoms. 2, too long bed rest: some pregnant women in the early stages of pregnancy, if there are symptoms of pre-eclampsia, doctors generally recommend that pregnant women absolutely bed rest. After a long period of bed rest, the pregnant woman will experience postural hypotension when she moves to the ground, manifesting as transient dizziness or even fainting. 3. Compression of the uterus: As pregnancy progresses, the enlarged uterus can compress the surrounding organs. When the uterus enlarges to a certain degree, the enlarged uterus can further compress the vena cava and cause transient dizziness due to the patient’s position. As mentioned above, dizziness can occur in early pregnancy, but it is not an organic lesion and pregnant women should not be overly stressed.