Bulimia nervosa
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Bulimia nervosa is an eating disorder characterised by recurrent binge eating, followed by compensatory behaviors, referred to as "purging".^[1] The most common form—practiced more than 75% of people with bulimia nervosa—is self-induced vomiting; fasting, the use of laxatives, enemas, diuretics, and overexercising are also common.^[2]

The word bulimia derives from the Latin (būlīmia) from the Greek βουλῑμια (boulīmia; ravenous hunger), a compound of βους (bous), ox + λῑμος (līmos), hunger.^[3]

Diagnosis

The criteria for diagnosing a patient with bulimia are:

• Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:
  • Eating, in a fixed period of time, an amount of food that is definitely larger than most people would eat under similar circumstances.
  • A lack of control over eating during the episode: a feeling that one cannot stop eating or control what or how much one is eating.
• Recurrent inappropriate compensatory behavior to prevent weight gain, such as: self-induced vomiting; misuse of laxatives, diuretics, or other medications; fasting; excessive exercise.
• Self-evaluation is unduly influenced by body shape and weight.
• The disturbance does not occur exclusively during episodes of anorexia nervosa.^[4]

There are two sub-types of bulimia nervosa: purging and non-purging.

• Purging bulimia is the more common of the two and involves self-induced vomiting (which may include use of emetics such as syrup of ipecac) and self-induced purging (which may include use of laxatives, diuretics, and enemas) to rapidly remove food from the body before it can be digested.
• Non-purging bulimia, which occurs in only approximately 6%-8% of cases, which involves excessive exercise or fasting after a binge to offset the caloric intake after eating. Purging-type bulimics may also exercise or fast, but as a secondary form of weight control.^[4]

The onset of bulimia nervosa is most likely during adolescence (between 13 and 20 years of age), with many sufferers relapsing in adulthood into episodic binging and purging even after initially successful treatment and remission.^[5]

Bulimia nervosa can be difficult to detect, compared to anorexia, because bulimics tend to look healthier and have fewer immediately-visible health complications. Many bulimics may also engage in significantly disordered eating and exercising patterns without meeting the full diagnostic criteria for bulimia nervosa.^[6]

Prevalence

There is little data on the incidence of bulimia nervosa in-the-large, on general populations. Most studies conducted thus far have been on convenience samples from hospital patients, high school or university students. These have yielded a wide range of results: between 0% and 2.1% of males, and between 0.3% and 7.3% of females.^[7]

Although bulimia is overwhelmingly a disease of young women, it can affect others. Former British Deputy Prime Minister John Prescott says he developed bulimia in his 60s ^[14].

Effects

These cycles often involve rapid and out-of-control eating, which may stop when the bulimic is interrupted by another person or the stomach hurts from overextension, followed by self-induced vomiting or other forms of purging. This cycle may be repeated several times a week or, in more serious cases, several times a day^[15], and may directly cause:

• Perimolysis, or the erosion of tooth enamel by gastric acids.
• Oral trauma, where habitual insertion by fingers or other objects cause lacerations to the lining of the mouth and throat.
• Chronic gastric reflux after eating.
• Esophagitis, or irritation of the esophagus by frequent contact with gastric acids.
• Dehydration and hypokalemia due to loss of fluids and potassium depletion.
• Swollen salivary glands.^[16]

Causes

Bulimia is related to deep psychological issues and feelings of lack of control. Sufferers often use the destructive eating pattern to feel in control over their lives.^[17] They may hide or hoard food and overeat when stressed or upset. They may feel a loss of control during a binge, and consume great quantities of food (over 20,000 calories).^[18] After a length of time, the sufferer of bulimia will find that they no longer have control over their binging and purging. The binging becomes an addiction that seems impossible to break. Recovery is very hard and often in the early stages of recovery the patient will gain weight as they are still binging but no longer purging, causing anxiety which will in turn cause the patient to revert back to bulimia.

There are higher rates of eating disorders in groups involved in activities that emphasize thinness and body type, such as gymnastics, modelling, dance, cheerleading, running, acting, rowing(lightweights/coxwains) and figure skating.^[19] Bulimia is more prevalent among Caucasians. In one study, diagnosis of bulimia was correlated with high testosterone and low estrogen levels, and normalizing these levels with combined oral contraceptive pills reduced cravings for fat and sugar.^[20]

Related disorders

Bulimics are much more likely than non-bulimics to have an affective disorder, such as depression or general anxiety disorder: a 1985 Columbia University study on female bulimics at New York State Psychiatric Institute found 70% had suffered depression some time in their lives (as opposed to 25.8% for adult females in a control sample from the general population), rising to 88% for all affective disorders combined.^[21] Another study by the Royal Children's Hospital in Melbourne on a cohort of 2000 adolescents similarly found that those meeting at least two of the DSM-IV criteria for bulimia nervosa or anorexia nervosa had a sixfold increase in risk of anxiety and a doubling of risk for substance dependency.^[22]

[1]

See also

• Anorexia nervosa
• Anorexia mirabilis
• Body dysmorphic disorder
• Body image
• Cachexia
• Calorie restriction
• Defensive vomiting
• Eating disorder not otherwise specified
• Fasting girls for a historical perspective on anorexia nervosa
• Female body shape
• Malnutrition
• Muscle dysmorphia ('reverse' anorexia nervosa)
• National Association of Anorexia Nervosa and Associated Disorders
• Orthorexia nervosa
• Pro-ana
• Purging disorder
• Refeeding syndrome

References