The causes of emotional instability in pregnant women may be related to hormonal changes in the body and pregnancy reactions. 1. Hormonal changes in the body: after a woman is pregnant, the level of estrogen in the body rises, and the body is affected by sex hormones, which is prone to endocrine disorders, which in turn affects the emotions of pregnant women, and mood swings and instability. This is a normal phenomenon and does not require treatment. 2. Pregnancy reactions: after pregnancy, there will be a variety of pregnancy reactions, such as dizziness, nausea, vomiting, loss of appetite, poor sleep and so on, which will make the pregnant woman feel uncomfortable, affecting the mood. Pregnant women in pregnancy mood fluctuations, there will be anxiety, aggression and other emotions, family members need to give understanding and support, timely psychological counseling. Pregnant women usually also need to pay attention to do some favorite things to ease the bad mood.