Anorexia nervosa: overview, symptoms, causes, treatment and complications

Core characteristics and subtypes

Diagnostic descriptions emphasize three core features: (1) restriction of food intake leading to low body weight; (2) an intense fear of gaining weight or becoming fat; and (3) a disturbance in how one’s body weight or shape is experienced. Clinically recognized subtypes include:

• Restricting type: weight loss achieved primarily through dieting, fasting or excessive exercise.
• Binge-eating/purging type: recurrent episodes of binge eating or purging (self-induced vomiting, misuse of laxatives or diuretics) in addition to restriction.

Causes and risk factors

No single cause explains anorexia; it usually arises from an interaction of biological, psychological and social influences. Risk factors include genetic vulnerability, personality traits such as perfectionism and high anxiety, social pressures around thinness, and life events or stressors. Cultural emphasis on appearance and dieting behaviors can contribute to onset. For more background and research summaries, consult further reading.

Signs, symptoms and medical complications

Behavioral and physical signs vary but commonly include strict food rules, avoidance of meals, extreme weight loss, ritualized eating, increased exercise, and mood changes. Medical consequences result from prolonged undernutrition and may affect many organ systems. Common problems include low blood pressure and slow heart rate, electrolyte disturbances, osteoporosis or low bone density, gastrointestinal symptoms, hormonal changes and, in those who purge, dental erosion and salivary gland enlargement. Because complications can be life-threatening, early medical assessment is important.

Diagnosis, differential and distinctions

Diagnosis is made by healthcare professionals based on clinical history, physical examination and assessment of eating attitudes and behaviors. Clinicians distinguish anorexia from other eating disorders such as bulimia nervosa—which involves recurrent binge eating with compensatory behaviors at a weight that is usually within or above a normal range—and avoidant/restrictive food intake disorder (ARFID), where restriction is not driven by body image concerns. Coexisting psychiatric conditions, such as depression, anxiety and obsessive-compulsive traits, are common and influence treatment planning.

Treatment approaches

Treatment typically combines medical monitoring, nutritional rehabilitation and psychological therapies. Early stabilization of medical complications and refeeding to restore weight are priorities. For adolescents, family-based treatment (often called the Maudsley method) is a leading evidence-based approach in which caregivers take an active role in refeeding and normalizing eating patterns; studies report meaningful improvements for many young patients. Adults may benefit from specialist psychotherapies such as cognitive-behavioral therapy adapted for eating disorders (CBT-ED), interpersonal therapy or newer approaches tailored to severe and enduring illness. Medications do not reliably reverse weight loss but may help treat co-occurring mood or anxiety disorders; some medications are used adjunctively under specialist supervision. For service directories and support options, see treatment resources and support networks.

Prognosis, prevention and notable facts

Outcomes vary. Some people recover fully with timely treatment, while others experience a chronic course with intermittent relapses. Earlier intervention, comprehensive care and family involvement generally improve chances of recovery. Anorexia has one of the highest mortality rates among psychiatric conditions due to medical complications and increased suicide risk, so taking concerns seriously and seeking professional help promptly are crucial. Public health efforts focus on prevention through awareness, reducing dieting culture pressures, and early identification in schools and primary care.