Anorexia Nervosa: Core Features, Medical Complications, and Treatment

Anorexia Nervosa: A Life-Threatening Eating Disorder

Defined by restriction of energy intake relative to requirements leading to significantly low body weight, intense fear of gaining weight, and disturbance in body weight/shape perception (DSM-5).

Subtypes

• Restricting type: weight loss via diet/fasting/exercise.
• Binge-eating/purging type: recurrent binge/purge episodes.

Medical Complications (Starvation Affects Every System)

System	Complications
Cardiovascular	Bradycardia, hypotension, arrhythmias, QT prolongation, sudden cardiac death
Endocrine	Amenorrhea, osteoporosis, low T3, cortisol dysregulation, growth retardation
GI	Gastroparesis, constipation, hepatic steatosis, pancreatitis (refeeding)
Renal/Electrolyte	Hypokalemia, hyponatremia, metabolic alkalosis (vomiting), acidosis (laxatives)
Neurologic	Brain volume loss, cognitive impairment, seizures, peripheral neuropathy
Hematologic	Anemia, leukopenia, thrombocytopenia
Dermatologic	Lanugo, dry skin, acrocyanosis, poor wound healing

Treatment

1. Medical stabilization (refeeding syndrome prevention: low-calorie start, phosphate monitoring).
2. Nutritional rehabilitation (gradual weight restoration).
3. Psychotherapy: FBT (adolescents), CBT-E, specialist supportive clinical management.
4. Psychopharmacology: Olanzapine for weight gain/anxiety; SSRIs for comorbid OCD/depression (after weight restoration).

Prognosis

~50% full recovery, 30% partial, 20% chronic; mortality ~5–10% per decade (highest of any psychiatric disorder). Early intervention improves outcomes.