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Anorexia Nervosa

What is Anorexia Nervosa?

Anorexia nervosa is an eating disorder in which a person intentionally limits the intake of food or beverage because of a strong drive for thinness and an intense fear of gaining weight. This can happen even if a person is already thin. The perception of body weight and shape is distorted and has an unduly strong influence on a person’s self-concept. The resulting weight loss and nutritional imbalance can lead to serious complications, including death.

Obsessions and anxiety about food and weight may cause monotonous eating rituals, including reluctance to be seen eating by others. It is not uncommon for people with anorexia nervosa to collect recipes and prepare food for family and friends, but not partake in the food that they prepared. They may also adhere to strict, intensive exercise routines to lose or keep off weight.

What Causes Anorexia Nervosa?

Anorexia nervosa does not have a single cause, but is related to many different factors. These factors are sometimes divided into predisposing, precipitating, and perpetuating factors, that make a person vulnerable to develop, trigger the onset, and maintain the eating disorder, respectively.  Anorexia nervosa often begins as simple dieting to "get in shape" or to "eat healthier" but progresses to extreme and unhealthy weight loss. Social attitudes toward body appearance, family influences, genetics, and neurochemical and developmental factors may contribute to the development and maintenance of anorexia nervosa. A personal or family history of anxiety, depression or obsessive-compulsive habits is common. Although families in which anorexia nervosa occurs were once labeled as having difficulties with conflict resolution, rigidity, intrusiveness, and over-protectiveness, it is now clear that parents do not cause eating disorders. Research suggests that certain areas of the brain function different with an active eating disorder.

Who is Affected by Anorexia Nervosa?

Anorexia nervosa not only affects individuals who have the diagnosis, but also their family, friends and loved ones. The diagnosis of anorexia nervosa has become more common over the past 20 years. Approximately 90 percent are women between 12 and 25 years of age. Initially found mostly in upper- and middle-class families, anorexia nervosa is now known to affect both sexes and span all ages, socioeconomic, ethnic, and racial groups.

What Kind of Person Tends to Get Anorexia Nervosa?

The typical profile of a person with anorexia nervosa is an adolescent to young adult female who is perfectionistic, hard-working, introverted, resistant to change and highly self-critical. They also tend to have low self-esteem based on body image distortion and avoid risky or potentially harmful behaviors or situations. However, regardless of the age, sex or other characteristics of the individual, weight control habits focused on reducing intake and increasing output of calories (particularly fats and carbohydrates) initially reduces anxiety, stress and negative mood by giving the person a sense of control in at least one are of her/his life. That is, a sense of mastery and accomplishment is achieved as weight is lost. Over time, these habits cause problems of their own that may increase anxiety, stress and negative mood.

What are the Different Types of Anorexia Nervosa?

There are two subgroups of behavior aimed at reducing caloric intake, including the following:

  • restrictive type - severely limits the intake of food and usually compulsively over-exercises.
  • binge/purge subtype – eats large amounts of food in a brief period of time (binges) and then compensates by intentionally vomiting (sometimes called purging), taking laxatives, exercising or fasting.

What are the Symptoms of Anorexia Nervosa?

The following are the most common symptoms of anorexia nervosa. However, each individual may experience symptoms differently. Symptoms may include:


  • Intense dieting or preoccupation with food
  • Intense fear of gaining weight , even when losing weight or at a very low weight
  • Distorted view of one's body weight, size, or shape; sees self as too fat, even when very underweight; expresses feeling fat, even when very thin
  • In females, absence of menstrual cycles without another cause
  • Hiding/discarding food
  • Counting calories, grams of fat in the diet
  • Rapid or excessive weight loss
  • Feeling tired, cold and weak
  • Lack of energy
  • Denial of feelings of hunger
  • Cold and blue hands and feet
  • Constipation
  • Dizziness or fainting
  • Hair loss
  • Slow heart rate
  • Absent or irregular menstruation
  • Excessive facial/body hair
  • Binge eating alternating with fasting
  • Vomiting or taking laxatives after over-eating
  • Compulsive or excessive exercise
  • Self-worth determined by weight or shape

Persons with anorexia nervosa may also be socially withdrawn, irritable, moody, and/or depressed. The symptoms of anorexia nervosa may resemble other medical problems or psychiatric conditions. Always consult your physician for a diagnosis.

How is Anorexia Nervosa Diagnosed?

Parents, family members, spouses, teachers, coaches, and instructors may be able to identify an individual with anorexia nervosa, although many persons with the disorder initially keep their illness very private and hidden. A detailed history of the individual's behavior from family, parents, and teachers, clinical observations of the person's behavior, contribute to the diagnosis.  Because a number of medical conditions can mimic some features of anorexia nervosa, a complete medical evaluation is needed.  Family members who note symptoms of anorexia nervosa in a loved one can help by seeking an evaluation and treatment early. Early treatment can often prevent future problems.

Anorexia nervosa, and the malnutrition that results, can adversely affect nearly every organ system in the body, increasing the importance of early diagnosis and treatment. Anorexia can be fatal. Consult your physician for more information.

Treatment for Anorexia Nervosa

Specific treatment for anorexia nervosa will be determined by a physician based on:

  • age, overall health, and medical history
  • extent of the symptoms
  • tolerance for specific meal plans, therapies, or medications
  • individual and family preferences

Anorexia nervosa is usually treated with a combination of medical care focused on nutritional rehabilitation and modification of behaviors related to eating and exercise to restore body weight and health, and family and/or individual therapy. Treatment should always be based on a comprehensive evaluation of the individual and family. Family therapy is focused on providing support and limit-setting on problem behaviors. Individual therapy usually includes both cognitive and behavioral techniques. Medication may be helpful if depressed moods or worrisome thoughts interfere with daily life.   Re-establishing a normal weight may relieve depression on its own, and anti-depressants are not effective at very low body weight. The frequent occurrence of medical complications and the possibility of death during the course of acute and rehabilitative treatment requires both your physician and a nutritionist to be active members of the management team. Families play a vital supportive role in any treatment process.

Possible Complications of Anorexia Nervosa

Medical complications are common in  anorexia nervosa.  Almost all complications are reversible with weight restoration related to healthy eating and physical activity.  Without treatment, complications persist and can worsen, and can be associated with death.  The short-term complications include, but are not limited to, the following:

  • Heart
    As a muscle, the heart is affected by both poor nutrition and exercise. In addition, the control mechanisms for the speed and regularity of the heartbeat are located in the central part of the brain. With prolonged low weight over several years, the heart muscle can eventually give out, causing death.
      •  irregular heartbeat
      • slow heartbeat
      • low blood pressure
      • fainting
      • with chronic low weight, fatal heart decompensation
  • Red blood cells that carry oxygen and the white blood cells that fight infection are often low.
  • Stomach. liver and intestines
    Loss of muscles in the gastrointestinal track results in shrinkage of the stomach and slow movement of foods through the track. Paradoxically, starvation can be associated with deposits of fat in the liver. 
    Full, bloated feeling after eating a small meal
    Feeling that the food does not empty from the
    Constipation due to loss of muscle in the gastrointestinal track
    Inflammation of the liver due to fatty deposits with starvation
  • Kidney
    Dehydration associated with anorexia results in highly concentrated urine. Increased urine production may also develop in patients when the kidneys ability to concentrate urine decreases.
  • Hormones
    Absence of the menstrual cycle is one of the hallmark symptoms of anorexia nervosa, and may precede significant weight loss..
  • Bones
    Persons with anorexia nervosa are at an increased risk for broken bones due to osteoporosis.

Biochemistry and Eating Disorders

To understand eating disorders, researchers have studied the neuroendocrine system, which is made up of a combination of the central nervous and hormonal systems.

The neuroendocrine system regulates multiple functions of the mind and body. It has been found that many of the following regulatory mechanisms may be, to some degree, disturbed in persons with eating disorders:

  • temperature regulation
  • sexual function
  • physical growth and development
  • appetite and digestion
  • sleep heart rate
  • kidney function
  • emotions
  • thinking
  • memory

Eating Disorders, Anxiety and Depression

As already noted, many people with eating disorders may also have anxiety, depression, and obsessive-compulsive traits.  There may be a link between anorexia nervosa and these other disorders.  For example

  • In the central nervous system, chemical messengers known as neurotransmitters control hormone production. The neurotransmitters serotonin and norepinephrine, which function abnormally in people who have depression, have been discovered to also have decreased levels in both acutely-ill anorexia and bulimia patients, and long-term recovered anorexia patients.
  • Research has shown that some patients with anorexia nervosa may respond well to selective serotonin reuptake inhibitors (SSRIs) after weight is restored.
  • People with anorexia, or certain forms of depression, seem to have higher than normal levels of cortisol, a brain hormone released in response to stress. It has been shown that the excess levels of cortisol in both persons with anorexia and in persons with depression are caused by a problem that occurs in, or near, the hypothalamus of the brain.

The first line of treatment for Anorexia nervosa is food. Improving nutrition alone often improves depression, although anxiety may increase initially.

Genetic/Environmental Factors Related to Eating Disorders

Because eating disorders tend to run in families, and female relatives are the most often affected, genetic factors are believed to play a role in the disorders.
But, other influences, both behavioral and environmental, may also play a role. Consider these facts from the National Institute of Mental Health:

  • Genetic factors are known to contribute to the anxiety, depression and obsessive-compulsive traits often occurring in anorexia nervosa.  This does NOT mean that parents who are anxious, depressed or have obsessive-compulsive traits CAUSE anorexia nervosa, but that there is an increased vulnerability to develop it.
  • “Innocent” teasing about body weight or appearance, especially by fathers and/or brother(s), may contribute to the onset of anorexia nervosa (precipitating cause).  .
  • Although most individuals with anorexia nervosa are adolescent and young adult women, these illnesses can also strike men and older women.
  • Anorexia nervosa is found most often in Caucasians, but these illnesses also affect African Americans and other races.
  • People pursuing activities or professions that emphasize thinness - such as modeling, dancing, gymnastics, wrestling, and long-distance running - are more susceptible to these disorders.

Prevention of Anorexia Nervosa

Preventive measures to reduce the incidence of anorexia nervosa are not known at this time. However, early detection and intervention can reduce the severity of symptoms, enhance the individual's normal growth and development, and improve the quality of life experienced by persons with anorexia nervosa.  Decreasing emphasis on weight and focusing on the balance between energy input and output can be useful.  Moreover, having healthy adult role models who do not talk about body shape or size, dieting, fat, or losing weight is helpful.  Also, encouraging healthy eating habits and realistic attitudes toward weight and diet may be an effective preventative measure.