Chart — Mental Health
Anorexia vs Bulimia Comparison
Both are serious eating disorders with distorted body image at the center, but they differ in weight, behavior, and which complications threaten the patient. The physical signs and electrolyte patterns are the most reliably tested distinctions.
Educational use only. For study and pattern recognition; diagnosis and treatment of eating disorders are provider- and program-directed. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Side by Side
| Feature | Anorexia Nervosa | Bulimia Nervosa |
|---|---|---|
| Core pattern | Restriction of intake; may have a binge-purge subtype | Recurrent binge eating + compensatory behaviors (vomiting, laxatives, fasting, exercise) |
| Body weight | Significantly low | Usually normal or slightly above — often not visibly apparent |
| Body image / insight | Distorted body image; often limited insight; sees illness as control | Distorted body image; often shame and more awareness that behavior is a problem |
| Telltale physical signs | Lanugo, cold intolerance, amenorrhea, bradycardia, hypotension, hair loss, osteoporosis | Dental enamel erosion, parotid swelling, Russell's sign (knuckle calluses), throat irritation |
| Key electrolyte/metabolic risk | Severe malnutrition; refeeding syndrome (hypophosphatemia) on nutritional rehab | Hypokalemia and hypochloremic metabolic alkalosis from purging — arrhythmia risk |
| Cardiac risk | Bradycardia, hypotension, arrhythmia from starvation | Arrhythmia from electrolyte loss |
| Nursing priority | Refeeding safety, supervised meals, weight restoration, monitor phosphate/K+/Mg | Interrupt binge-purge cycle, monitor potassium, supervise post-meal period, address shame |
The Shared Danger
Weight is a poor proxy for risk. A normal-weight bulimic patient can have life-threatening hypokalemia, and an anorexic patient is most fragile exactly when treatment begins — refeeding syndrome. Both carry elevated suicide risk. The takeaway: assess the electrolytes and the heart, not the silhouette.
NCLEX Pearls
- ✦Lanugo and bradycardia → anorexia; Russell’s sign, enamel erosion, and parotid swelling → bulimia.
- ✦Bulimia’s headline lab risk is hypokalemia from purging (arrhythmia); anorexia’s is refeeding hypophosphatemia.
- ✦Normal body weight does not mean low risk — bulimia patients are often normal weight.
- ✦Supervise meals and the period after; address feelings and control rather than commenting on weight.
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with American Psychiatric Association (DSM-5-TR) · American Psychiatric Nurses Association (APNA) · SAMHSA. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →