Anorexia nervosa is a psychiatric diagnosis that describes an eating disorder characterized by low body weight and body image distortion with an obsessive fear of gaining weight. Individuals with anorexia often control body weight by voluntary starvation, purging, vomiting, excessive exercise, or other weight control measures, such as diet pills or diuretic drugs. It primarily affects adolescent females, however approximately 10% of people with the diagnosis are male. Anorexia nervosa is a complex condition, involving psychological, neurobiological, and sociological components.
"Anorexia nervosa" is frequently shortened to "anorexia" in both the popular media and scientific literature. This is technically incorrect, as the term "anorexia" used separately refers to the medical symptom of reduced appetite.
Physical
Anorexia nervosa can put a serious strain on many of the body's organs and physiological resources, particularly on the structure and function of the heart and cardiovascular system, with slow heart rate (bradycardia) and elongation of the QT interval seen early on. People with anorexia typically have a disturbed electrolyte balance, particularly low levels of phosphate, which has been linked to heart failure, muscle weakness, immune dysfunction, and ultimately death. Those who develop anorexia before adulthood may suffer stunted growth and subsequent low levels of essential hormones (including sex hormones) and chronically increased cortisol levels. Osteoporosis can also develop as a result of anorexia in 38-50% of cases, as poor nutrition leads to the retarded growth of essential bone structure and low bone mineral density. Anorexia does not harm everyone in the same way. For example, evidence suggests that the results of the disease in adolescents may differ from those in adults.
Changes in brain structure and function are early signs of the condition. Enlargement of the ventricles of the brain is thought to be associated with starvation, and is partially reversed when normal weight is regained. Anorexia is also linked to reduced blood flow in the temporal lobes, although since this finding does not correlate with current weight, it is possible that it is a risk trait rather than an effect of starvation.
Other effects may include the following:
* Extreme weight loss
* Body mass index less than 17.5 in adults, or 85% of expected weight in children
* Stunted growth
* Endocrine disorder, leading to cessation of periods in girls (amenorrhoea)
* Decreased libido; impotence in males
* Starvation symptoms, such as reduced metabolism, slow heart rate (bradycardia), hypotension, hypothermia and anemia
* Abnormalities of mineral and electrolyte levels in the body
* Thinning of the hair
* Growth of lanugo hair over the body
* Constantly feeling "cold"
* Zinc deficiency
* Reduction in white blood cell count
* Reduced immune system function
* Pallid complexion and sunken eyes
* Creaking joints and bones
* Collection of fluid in ankles during the day and around eyes during the night
* Tooth decay
* Constipation
* Dry skin
* Dry or chapped lips
* Poor circulation, resulting in common attacks of 'pins and needles' and purple extremities
* In cases of extreme weight loss, there can be nerve deterioration, leading to difficulty in moving the feet
* Headaches
* Brittle fingernails
* Bruising easily
Psychological
* Distorted body image
* Poor insight
* Self-evaluation largely, or even exclusively, in terms of their shape and weight
* Pre-occupation or obsessive thoughts about food and weight
* Perfectionism
* Obsessive compulsive disorder (OCD)
* Belief that control over food/body is synonymous with being in control of one's life
* Refusal to accept that one's weight is dangerously low even when it could be deadly
Emotional
* Low self-esteem and self-efficacy
* Intense fear about becoming overweight
* Clinical depression or chronically low mood
* Mood swings
Interpersonal and social
* Withdrawal from previous friendships and other peer-relationships
* Deterioration in relationships with the family
* Denial of basic needs, such as food and sleep
Behavioral
* Excessive exercise, food restriction
* Secretive about eating or exercise behavior
* Fainting
* Self-harm, substance abuse or suicide attempts
* Very sensitive to references about body weight
* Aggressive when forced to eat "forbidden" foods
Diagnostic issues and controversies
The distinction between the diagnoses of anorexia nervosa, bulimia nervosa and eating disorder not otherwise specified (EDNOS) is often difficult to make in practice and there is considerable overlap between patients diagnosed with these conditions. Furthermore, seemingly minor changes in a patient's overall behavior or attitude (such as reported feeling of 'control' over any bingeing behavior) can change a diagnosis from 'anorexia: binge-eating type' to bulimia nervosa. It is not unusual for a person with an eating disorder to 'move through' various diagnoses as his or her behavior and beliefs change over time.
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