Water intoxication in anorexia nervosa

OBJECTIVE AND METHOD: A case of water intoxication in a patient with anorexia nervosa is reported. RESULTS: Differently from the other cases previously reported, the patient had a long duration of illness (13 years). A compulsory treatment was necessary since the patient refused any cooperation and her weight had dropped to 19.5 kg (body mass index = 8.3). After a slow weight recovery and a multidisciplinary inpatient treatment of 15 months, the patient started an outpatient treatment. One month later she complained of headache, vomiting, and grand-mal seizures with hyponatremia, hypokalemia, hypochloremia, and low urine osmolarity. Later, we were able to learn from her that some weeks before she had begun to drink large amounts of water before the weight control visits to maintain the target weight. After this episode, she carried on the abnormal drinking habit, although she knew the risks related to excessive drinking. DISCUSSION: Studies on larger samples are needed to understand the risk factors for abnormal drinking habits in anorexia nervosa.