Eating Disorders – Anorexia Nervosa
Anorexia nervosa is characterized by severe disturbances in eating behaviour with voluntary restriction of food intake as its salient feature. The main purpose of patients with anorexia nervosa is to stay thin and have a weight below normal. It is more prevalent in areas wherein food supply is plenty and being thin is perceived to be ideal and attractive. Women are more prone in developing anorexia nervosa compared to men, and those who are in ballet and in modelling, wherein being thin is a goal, are at a greater risk of developing this disorder.
The cause of anorexia nervosa is believed to be an interplay of psychological, biological and cultural factors. A history of sexual and physical abuse could also increase the risk of developing anorexia nervosa. Anorexia nervosa usually starts as a simple diet plan among female adolescents and adults with the aim of losing weight. As weight loss progresses, they eventually fear gaining weight hence a further decrease in food and caloric intake eventually leading to this disorder.
Patients with anorexia nervosa may present with decrease cold tolerance and decrease gastrointestinal motility due to decrease oral intake and dehydration. Amenorrhea (no menses) is usually present among anorexia nervosa patients. Laboratory findings would include anemia, low blood sugar, slightly elevated blood urea nitrogen and serum creatinine due to dehydration, electrolyte imbalances like hyponatremia (low sodium), hypokalemia (low potassium), hypophosphatemia (low phosphate) and hypomagnesemia (low magnesium). Anorexia nervosa could also present with cardiac abnormalities like decrease cardiac output and changes in the ECG.
Restoration of 90% of predicted body weight is the primary goal in the treatment of anorexia nervosa. Physical and psychological concerns should also be addressed in these patients and education regarding the importance of maintaining adequate nutritional status should be given to them. Some patients would require hospitalization depending on their current weight and the presence of any complications. Assistance of psychiatrists and psychologists are usually necessary to help patients with anorexia nervosa overcome the psychological difficulty in complying with the increase caloric requirement.
The prognosis of anorexia nervosa is variable; some patients would eventually fully recover while some would eventually have psychological and physical morbidities. The mortality associated with anorexia nervosa is one of the highest among psychiatric disorders secondary to chronic starvation or to suicide.
Harrison’s Principles of Internal Medicine 18th ed
Bulimia nervosa is an eating disorder characterized by severe disturbances in one’s eating behavior. It is characterized by increasing food intake followed by compensatory behaviors like self-induced vomiting.