Usually, patients with gestational diabetes mellitus may have no obvious symptoms, and abnormal elevation of blood glucose is usually found during maternity checkups or self-testing of blood glucose by pregnant women. Some pregnant women may have symptoms such as dry mouth, excessive drinking, excessive urination, and excessive eating. Gestational diabetes mellitus refers to diabetes mellitus that is first detected or develops during pregnancy, i.e., pregnancy comes first and diabetes mellitus manifests later. The main pathogenesis is unknown for the time being and may be related to increased glucose requirement, insulin resistance and relative deficiency in insulin secretion. Symptoms such as abnormally high blood glucose, thirst, polydipsia, polyphagia and polyuria may occur. In addition, gestational diabetes mellitus, if left untreated, may cause serious complications and even jeopardize the life of mother and child. Patients are advised to go to the emergency room of the hospital in time and take oral hypoglycemic drugs and insulin injections as prescribed by the doctor.