The symptoms of irritability can occur in pregnant women. What causes irritability in women during pregnancy: 1. If this symptom occurs in the early stages of pregnancy, it is usually one of the normal early pregnancy reactions, which occurs due to changes in endocrine function after pregnancy, causing disorders of the plant nervous system. 2. Abnormal thyroid function, some women will have abnormal thyroid function during pregnancy. The reason for this is the change in the endocrine function after pregnancy, making the plant nervous system disorder. 2, abnormal thyroid function, some women will have abnormal thyroid function during pregnancy, manifested as hyperthyroidism or hypothyroidism, which may cause symptoms of heartburn. 3, physical discomfort, the process of pregnancy is a relatively long process, due to a variety of functional changes will make the pregnant woman’s body some discomfort, when there are obvious symptoms of physical discomfort, pregnant women will show manifestations of irritability, depression, excessive mood swings.