Bulimia Nervosa Workup

Updated: Apr 14, 2023
  • Author: Donald M Hilty, MD, MBA; Chief Editor: David Bienenfeld, MD  more...
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Laboratory Studies

See the list below:

  • Comprehensive blood chemistry panel: This is important in detecting possible occult metabolic complications of bulimia. With significant vomiting, hypokalemic metabolic alkalosis is possible. Among patients with significant laxative abuse, normokalemic metabolic acidosis may occur. Hyponatremia, hypocalcemia, hypophosphatemia, and hypomagnesemia should be ruled out. Those who have significant intravascular depletion may have elevated blood urea nitrogen levels.

  • Complete blood cell count: This is used to exclude anemia or other occult hematologic abnormalities.

  • Urinalysis: Urine specific gravity may reflect the state of hydration. Some patients may water load in an attempt to gain some weight before their health care visit.

  • Urine toxicology: Comorbid substance abuse should be ruled out with a urine toxicology screen. [77]

  • Pregnancy test: This should always be obtained to rule out pregnancy in female patients presenting with amenorrhea.

  • Amylase: Hyperamylasemia is found in up to 30% of persons with significant vomiting because of hypersecretion from the salivary glands. This may offer a rough measure of purging activity or suggest the presence of purging in patients who are suspected of purging but who deny doing it. However, serial amylase levels are not sufficiently sensitive to offer a useful clinical marker to follow the course of purging.


Imaging Studies

Imaging studies are rarely routinely indicated or ordered for uncomplicated or typical cases of bulimia nervosa (BN). Nonetheless, there has been growing interest in the use of neuroimaging techniques to explore the structural and functional brain changes that take place in those with eating disorders, though the majority of research has focused on patients with anorexia nervosa (AN). A systematic review of 32 papers found a small number of consistent findings in individuals in the acute phase of illness with BN or binge-eating disorder (BED) including: volume reduction and increases across a range of areas; hypoactivity in the frontostriatal circuits; and aberrant responses in the insula, amygdala, middle frontal gyrus and occipital cortex to a range of different stimuli or tasks; a link between illness severity in BN and neural changes; and diminished attentional capacity and early learning. [78]  Additional research is suggested related to the findings of reduced cortical volumes and diminished activity in regions associated with self-regulation (e.g. frontostriatal circuits) and in exploring responses to disorder-related stimuli in those with BN or BED.


Other Tests


Because of the potential for arrhythmias and cardiomyopathy as possible complications, an electrocardiogram should be performed in patients who are very thin, complaining of palpitations, or have other signs or symptoms suggestive of cardiovascular concern. Prolonged QTc, especially in the setting of hypokalemia, heighten the risk for cardiac decompensation in this population. [6]


Because of the potential for osteoporosis, a dual energy absorptiometry (DEXA) scan may be useful, particularly for patients with irregular menses, mood disorders, and/or who smoke cigarettes.


Routine neuropsychological testing is not indicated. When specific abnormalities are found in mental status testing, or when histories of learning impairment are present, neuropsychological testing may show decision-making abnormalities, as well as impairment in word recall, abstraction, attention, visuospatial functioning, and problem solving. [79, 80]