Overview of bulimia nervosa

Bulimia nervosa is a common eating disorder, characterised by recurrent episodes of binge eating followed by compensatory behaviour to prevent weight gain. It has a community lifetime prevalence of approximately 2% in females and 0.5% in males and has a usual onset during older adolescence and young adulthood. People with a history of trauma (physical, sexual or emotional abuse), restrictive dieting, family history of an eating disorder, or high body mass index (BMI) may be at increased risk of developing bulimia nervosa. Patients usually present many years after the onset of the disorder with concerns about weight loss or medical and psychiatric comorbidities, such as depression and anxiety.

The signs and symptoms of bulimia nervosa include:

  • regular episodes of uncontrolled overeating over a discrete period of time (binge eating), followed by
  • regular extreme weight-control methods to counteract the perceived and feared effects of overeating, such as purging (eg self-induced vomiting, laxative or diuretic abuse), driven exercise, fasting
  • overvaluation of body weight or shape as an expression of self-worth
  • body weight in the adequate to obese range.

Patients with bulimia nervosa often present with psychological comorbidities (eg depression, anxiety). Patients with bulimia nervosa may present with medical complications such as hypokalaemia or dehydration from purging behaviours.

Screening questions can be used to detect the possible presence of an eating disorder in those considered to be at risk. The SCOFF questionnaire is a screening tool validated for use in primary care.

If a patient meets all the criteria for bulimia nervosa, except their symptoms last for a shorter duration (ie less than 3 months) and the purging behaviours occur at a lower frequency (ie less than once weekly), they are diagnosed with subthreshold bulimia nervosa . Although subthreshold bulimia nervosa is a diagnostic subcategory of Other specified feeding or eating disorder (OSFED), it is managed the same as bulimia nervosa (see Principles of managing bulimia nervosa).