Bulimia Nervosa: Medical Complications, Diagnostic Evaluation, and Treatment Hierarchy

Bulimia nervosa (BN) is characterized by recurrent binge eating with inappropriate compensatory behaviors (self-induced vomiting, laxative/diuretic/enema misuse, fasting, excessive exercise) ≥1×/week for 3 months, with self-evaluation unduly influenced by body shape/weight. It's a serious, potentially lethal condition requiring multidisciplinary intervention.

Medical Complications by System

System	Complications	Mechanism
Electrolyte / Renal	Hypokalemia, hypochloremic metabolic alkalosis, hyponatremia, renal insufficiency, rhabdomyolysis	Vomiting/laxative/diuretic losses; volume depletion
Cardiac	QT prolongation, arrhythmias, cardiomyopathy, mitral valve prolapse, sudden death	Electrolyte shifts, ipecac toxicity (historical), autonomic dysregulation
GI / Dental	Erosive esophagitis, Barrett's esophagus, Mallory-Weiss tears, gastric rupture, dental erosion (perimolysis), caries, sialadenosis	Acid exposure; mechanical trauma
Endocrine	Hypothalamic amenorrhea, osteopenia/osteoporosis, thyroid dysregulation (euthyroid sick)	Energy deficit, estrogen deficiency, leptin suppression
Neurologic	Seizures (hyponatremia), peripheral neuropathy (vitamin deficiency), cerebral edema (rapid refeeding)	Electrolyte / nutritional
Dermatologic	Russell's sign (calloused knuckles), lanugo, dry skin, hair loss	Self-induced vomiting; malnutrition

Diagnostic Evaluation

• Physical: Vitals (orthostatics critical), BMI, parotid enlargement, Russell's sign, dental exam, skin, neurologic.
• Labs: BMP (K⁺, Cl⁻, CO₂, BUN/Cr, glucose), Mg, Phos, CBC, LFTs, TSH, estradiol, FSH/LH, 25(OH)D, B12, ferritin, EKG (QTc).
• Imaging: DEXA (Z-score < -2.0 → osteoporosis); upper endoscopy if GI alarm symptoms.

Treatment Hierarchy

1. Medical Stabilization (Priority 1): Electrolyte repletion (IV K⁺ if <2.5 or symptomatic), cardiac monitoring, refeeding protocol if severely malnourished.
2. CBT-E (BN Protocol): 20 sessions. Self-monitoring, regular eating, exposure to fear foods, cognitive restructuring of shape/weight overvaluation, relapse prevention. Gold standard.
3. Medication: Fluoxetine 60 mg/day (only FDA-approved for BN); reduces binge/purge frequency ~50%. Adjunctive topiramate (off-label) if inadequate response.
4. Nutritional Rehabilitation: Registered dietitian (CEDRD preferred); mechanical eating → intuitive eating; address fear foods.
5. Higher Levels of Care: IOP/PHP/Residential if medical instability, suicidality, outpatient failure.

Recovery Metrics

• Abstinence from binge/purge ≥4 weeks = remission
• ≥1 year = recovery
• Weight restoration (if underweight) + menstrual return + normalized bone density + psychosocial functioning

Early intervention prevents irreversible complications (cardiac, skeletal, dental). Multidisciplinary teams save lives. If you or someone you know is struggling, contact NEDA (1-800-931-2237) or find a CEDS (Certified Eating Disorder Specialist) at iaedp.org.