Bulimia Nervosa

Bulimia nervosa is an eating disorder marked by recurrent episodes of binge eating accompanied by inappropriate compensatory behaviors (laxatives or diuretics use, self-induced vomiting, fasting, or excessive exercise) to counteract the effects of binge eating and prevent weight gain. These episodes occur at least twice weekly for at least 3 months. Patients have normal body weight (or are slightly overweight). Treatment consists of a combination of psychotherapy and pharmacotherapy.

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Bulimia nervosa is an eating disorder characterized by recurrent episodes of binge eating (consuming a larger-than-appropriate amount of food in a set period of time) accompanied by inappropriate compensatory behavior (purging).


  • Lifetime prevalence: 1%
  • Women aged 18–35 most commonly affected
  • More prevalent in women
  • Later onset in adolescence than in anorexia nervosa


  • No consensus on pathophysiology
  • May be related to abnormal functioning of corticolimbic circuits (involved in appetite) 
  • Efficacy of antidepressants as well as established link between serotonin and satiety suggest the involvement of serotonin and norepinephrine in the pathophysiology of bulimia.



  • Diagnosis is clinical, based on specific criteria:
    • Recurrent episodic binge eating followed by feelings of disgust and guilt
    • Recurrent inappropriate compensatory behaviors to prevent weight gain, including:
      • Use of laxatives or diuretics
      • Self-induced vomiting
      • Fasting
      • Excessive exercise
    • Excessive emphasis on body shape or weight
  • At least 2 episodes per week for 3 months
  • Binge eating and compensatory behavior do not occur exclusively during episodes of anorexia nervosa.

Physical exam

Specific exam findings can be suggestive of eating disorders:

  • BMI > 18.5 kg/m2
  • Easy fatigability 
  • Orthostatic hypotension
  • Physical signs consistent with self-induced vomiting: 
    • Swelling of the salivary glands
    • Dental caries
    • Scars or calluses on the hand from contact with the teeth (Russell sign)
  • Dehydration
  • Menstrual irregularities
  • Mallory-Weiss syndrome
  • Bloating
  • Constipation

Lab findings

Though not diagnostic, certain lab findings are suggestive of bulimia: 

  • Increased serum amylase due to parotid gland hypertrophy
  • Electrolyte abnormalities (hypokalemia, hypochloremia), which occur due to vomiting and excessive renal loss of potassium
  • Metabolic alkalosis (due to recurrent acid loss in vomit)



The 1st-line treatment is a combination of psychotherapy and pharmacotherapy. 

  • Psychotherapy:
    • The mainstay of treatment is CBT.
    • Goal is to normalize patient’s eating behavior and avoid destructive binge-eating episodes.
    • CBT alone results in better outcomes than medications alone.
  • Pharmacotherapy:
    • Selective serotonin reuptake inhibitors (SSRIs; e.g., fluoxetine) are preferred.
    • Other options: tricyclic antidepressants, monoamine oxidase inhibitors, and mood stabilizers
    • Bupropion is contraindicated in bulimia nervosa (may induce seizures). 
  • Adjunct therapy:
    • Nutritional rehabilitation: need a nutritionist guide to help replace nutritional stores
  • Hospitalization may be necessary in cases of:
    • Failure of outpatient treatment
    • Self-injuring behavior 
    • Increased risk of suicidal tendencies
    • Severe electrolyte or metabolic abnormality


  • Higher rates of remission and recovery than in anorexia nervosa
  • Patients with comorbid substance use generally have worse outcomes. 

Differential Diagnosis

  • Anorexia nervosa: an eating disorder characterized by intense fear of gaining weight, restricted dietary habits, and distorted body image. Patients affected by anorexia nervosa are usually underweight and reluctant to seek medical help. Treatment involves CBT with antidepressant medication as an adjunct. Extreme cases may require hospitalization.
  • Binge-eating disorder: an eating disorder marked by recurrent episodes of binge eating without inappropriate compensatory behavior, resulting in fluctuating body weight. Episodes occur at least once a week for 3 months. Treatment consists of a combination of psychotherapy and pharmacotherapy.
  • Rumination disorder: repeated regurgitation of food, which may be re-chewed, re-swallowed, or spit out, and which is not due to a general medical condition (e.g., GERD). Treatment involves multiple CBT techniques, including biofeedback psychotherapy, as well as medication when appropriate (e.g., proton pump inhibitors).
  • Kleine-Levin syndrome (KLS): also known as “sleeping beauty syndrome,” a very rare sleep disorder that includes recurrent episodes of hypersomnia that presents with behavioral or cognitive abnormalities, including compulsive eating and hypersexuality. Ptients with KLS do not have a crippling fear of weight gain or place a great deal of self-worth on their body weight and shape, unlike patients with bulimia nervosa. 


  1. Kessler RC, et al. (2013). The prevalence and correlates of binge eating disorder in the World Health Organization World Mental Health Surveys. Biol Psychiatry. 73(9), 904–914. https://pubmed.ncbi.nlm.nih.gov/23290497/
  2. Norris M., et al. (2014). Exploring avoidant/restrictive food intake disorder in eating disordered patients: a descriptive study. Int J Eat Disord. 47(5), 495–499. https://pubmed.ncbi.nlm.nih.gov/24343807/
  3. Mitchell, JE, Crow S. (2006). Medical complications of anorexia nervosa and bulimia nervosa. Curr Opin Psychiatry. 19(4), 438–43. https://pubmed.ncbi.nlm.nih.gov/16721178/
  4. Sadock BJ, Sadock VA, Ruiz P. (2014). Kaplan and Sadock’s synopsis of psychiatry: Behavioral sciences/clinical psychiatry (11th ed.). Chapter 15, Feeding and Eating Disorders. Philadelphia, PA: Lippincott Williams and Wilkins. pp. 509–532.
  5. Westmoreland P. (2017). Feeding and eating disorders. Retrieved May 27, 2021, from https://doi.org/10.2310/im.13038
  6. Westmoreland P. (2018). Clinical management of feeding and eating disorders. Retrieved May 27, 2021, from https://doi.org/10.2310/im.13039

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