Bulimia nervosa has biological causes such as family genetics and psychology, as well as social and cultural causes such as excessive comparison and family conflicts. 1. Biological causes: Bulimia nervosa is mostly caused by family genetics, and the influence of genes is still unclear; psychological factors, such as obsessive-compulsive disorder, self-esteem, emotional instability, depression, etc., may show bulimic manifestations in order to relieve one’s discomfort. 2. Social and cultural reasons: excessive comparison, recent stress, family conflicts, and prolonged late nights can also lead to appetite and other abnormal eating habits. If the symptoms are not relieved after lifestyle modification, one should consult a doctor in time to clarify the cause of the disease under the guidance of a professional physician and undergo psychotherapy and medication.