Anorexia Nervosa

Symptoms | Causes | Diagnostic Criteria | Treatments

Anorexia nervosa is a mental illness characterized by an intense fear of gaining weight, persistent caloric restriction, behaving in ways that interfere with weight gain, and a disturbance in self-perceived weight or shape. Someone suffering with anorexia nervosa will maintain a body weight that is below a minimally normal level for age, sex, development trajectory, and physical health, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

Anorexia nervosa is most commonly experienced by females. However, men can also experience the symptoms of this mental disorder. According to the DSM-5, less is known about the prevalence among males, but anorexia nervosa is far less common in males than in females, with clinical populations generally reflecting approximately a 10:1 female-to-male ratio.

People suffering from anorexia nervosa are often, but not always, malnutritioned and well below what their weight should be for their age and height. With this in mind, it is not uncommon for their anorexia nervosa to also be the cause of other health problems, due to malnutrition and starving oneself. While not every anorexic is very underweight, most are.

According to the DSM-5, anorexia nervosa commonly begins during adolescence or young adulthood. This condition rarely begins before puberty or after age 40, but cases of both early and late onset have been described. The onset of anorexia nervosa is often associated with a particular stressful life event. Nevertheless, the development of anorexia nervosa, just as is the case with any other mental disorder, is predicated upon genetics and environmental factors.

Anorexia Nervosa Symptoms

Some common symptoms of anorexia nervosa are as follows:

  • Extreme weight loss
  • Thin appearance
  • Dehydration
  • Lethargy
  • Light-headedness
  • Thinning hair / hair falling out
  • Absence of menstrual cycle
  • Constipation and abdominal pain
  • Irregular heart rhythms
  • Exercising excessively
  • Frequently skipping meals or refusal to eat
  • Denial of hunger or making excuses for not eating
  • Spitting food out after chewing
  • Lying about how much food has been eaten
  • Low blood pressure
  • Constantly weighing oneself to check current weight
  • Frequently checking their appearance in the mirror for signs of weight gain
  • Flat mood (lack of emotion)
  • Eroded teeth and calluses on the knuckles from induced vomiting

Causes of Anorexia Nervosa

Just as is the case with any other mental disorder, anorexia nervosa is likely caused by a combination of genetic and environmental factors. Anorexia nervosa commonly begins during adolescence or young adulthood. The onset of anorexia nervosa is often associated with a stressful life event, such as leaving home for college, for example.

Furthermore, There is an increased risk of anorexia nervosa and bulimia nervosa among first-degree biological relatives of individuals with the disorder. Additionally, individuals who develop anxiety disorders or display obsessional traits in childhood are at increased risk of developing anorexia nervosa, according to the DSM-5.

According to the Center for Discovery, evidence from twin studies has shown that there may be a significant genetic component to developing this eating disorder. Studies have shown that there may possibly be a 50 to 80 percent heritability factor contributing to the development of anorexia nervosa. Indeed, specific genes have been discovered that may contribute to the development of this condition.

Diagnostic Criteria

To get diagnosed with anorexia nervosa, one would need to get a psychiatric evaluation by a licensed mental health professional. This will typically entail being asked several questions about their eating habits, their thoughts about their body image, as well as how their thoughts and behaviors surrounding their anxiety has negatively impacted their daily life.

According to the DSM-5, some of the diagnostic criteria of anorexia nervosa are as follows:

A. Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected.

B. Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.

C. Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.

Coding note: The ICD-9-CM code for anorexia nervosa is 307.1, which is assigned regardless of the subtype. The ICD-10-CM code depends on the subtype.

Specify whether:

Restricting type: During the last 3 months, the individual has not engaged in recurrent episodes of binge eating or purging behavior (i.e., self-induced vomiting or the misuse of laxatives, diuretics, or enemas).

Binge-eating/purging type: During the last 3 months, the individual has engaged in recurrent episodes of binge eating or purging behavior (i.e., self-induced vomiting or the misuse of laxatives, diuretics, or enemas).

Specify current severity:

The minimum level of severity is based, for adults, on current body mass index (BMI) or, for children and adolescents, on BMI percentile.

Mild: BMI ≥ 17 kg/m2

Moderate: BMI 16-16.99 kg/m2

Severe: BMI 15-15.99 kg/m2

Extreme: BMI < 15 kg/m2

Reference: Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5)

Anorexia Nervosa Treatments

There are many options available for those with anorexia nervosa looking to seek treatment. Psychotherapy, medication, and medical care (for physical health issues) should all be considered. Psychotherapy, or talk therapy, is done by a licensed mental health therapist or counselor who uses scientifically-based methods to help reduce one’s symptoms of anorexia. Therapies such as cognitive behavioral therapy (CBT) is often used to help treat this condition. While not every therapist specializes in the same conditions, you will likely want to try and find a therapist who has some experience treating people with anorexia nervosa.

While there are no psychiatric medications that are designed to treat the specific symptoms of anorexia, there are some medications that may significantly help, nonetheless. Since anorexia nervosa is often considered to be an anxiety disorder, anti-anxiety medications, as well as anti-depressants are often prescribed. These drugs are classified as selective serotonin reuptake inhibitors (SSRIs). These types of medications are commonly prescribed for those suffering from anxiety disorders, such as OCD, PTSD, major depression, and eating disorders.


  • Diagnostic and Statistical Manual of Mental Disorders (DSM-5)

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