Bulimia nervosa is a serious eating disorder where people eat large amounts of food and then purge to get rid of the extra calories in unhealthy ways like forced vomiting or excessive exercise. People with bulimia may exhibit behaviors like binge eating followed by purging, secrecy around eating, lack of control over eating, mood swings and depression. Physical signs include calluses on hands from induced vomiting, puffy cheeks, discolored teeth, and fluctuations in weight despite purging. Genetic, psychological, and cultural factors can contribute to the development of bulimia.