Anorexia nervosa has no single cause; it develops when inherited biology, brain and hormone differences, personality traits, and social pressures act together.
In everyday medical use, "anorexia" alone means loss of appetite from illness or medication, while anorexia nervosa is an eating disorder driven by restriction and fear of weight gain. Family and twin studies show that risk runs in families, and traits like perfectionism, anxiety, and rigid thinking make restriction feel rewarding rather than distressing. Common triggers include dieting, puberty, weight-related comments, stressful life changes, trauma, and sports or jobs that emphasize a lean body. Once weight loss starts, starvation itself alters brain chemistry, mood, and thinking, which keeps the cycle running and makes willpower explanations wrong. Eating regular meals, limiting appearance-focused social media, and talking early with a clinician or dietitian help interrupt the pattern before it becomes entrenched.
How anorexia is treated
Common questions
What causes Anorexia?
Anorexia nervosa has no single cause. It develops when genetic and biological factors combine with psychological traits and social pressures. Twin and family studies show inherited risk, and differences in brain circuits that handle reward, anxiety, and appetite contribute. Perfectionism, anxiety, obsessive traits, and low self-esteem raise risk. Triggers often include dieting, puberty, weight-related teasing, stress or trauma, and activities that reward thinness. Once restriction begins, starvation itself changes brain function and thinking, which sustains the illness. It affects all genders, ages, body sizes, and backgrounds, and diagnosis and treatment need a clinician.