Anorexia

The most commonly used criteria for diagnosing anorexia are from the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) and the World Health Organization's International Statistical Classification of Diseases and Related Health Problems (ICD).

Although biological tests can aid the diagnosis of anorexia, the diagnosis is based on a combination of behavior, reported beliefs and experiences, and physical characteristics of the patient. Anorexia is typically diagnosed by a clinical psychologist, psychiatrist or other suitably qualified clinician. Notably, diagnostic criteria are intended to assist clinicians, and are not intended to be representative of what an individual sufferer feels or experiences in living with the illness.

The full ICD-10 diagnostic criteria for anorexia nervosa can be found here, and the DSM-IV-TR criteria can be found here.

To be diagnosed as having anorexia nervosa, according to the DSM-IV-TR, a person must display:

Refusal to maintain body weight at or above a minimally normal weight for age and height (e.g., weight loss leading to maintenance of body weight less than 85% of that expected; or failure to make expected weight gain during period of growth, leading to body weight less than 85% of that expected).

Intense fear of gaining weight or becoming obese.

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 denial of the seriousness of the current low body weight.

The absence of at least three consecutive menstrual cycles (amenorrhea), in women who have had their first menstrual period but have not yet gone through menopause (postmenarcheal, premenopausal females).

Or other eating related disorders.

Furthermore, the DSM-IV-TR specifies two subtypes:

Restricting Type: during the current episode of anorexia nervosa, the person has not regularly engaged in binge-eating or purging behavior (that is, self-induced vomiting, over-exercise or the misuse of laxatives, diuretics, or enemas)

Binge-Eating Type or Purging Type: during the current episode of anorexia nervosa, the person has regularly engaged in binge-eating OR purging behavior (that is, self-induced vomiting, over-exercise or the misuse of laxatives, diuretics, or enemas).

The ICD-10 criteria are similar, but in addition, specifically mention

The ways that individuals might induce weight-loss or maintain low body weight (avoiding fattening foods, self-induced vomiting, self-induced purging, excessive exercise, excessive use of appetite suppressants or diuretics).

Certain physiological features, including "widespread endocrine disorder involving hypothalamic-pituitary-gonadal axis is manifest in women as amenorrhoea and in men as loss of sexual interest and potency. There may also be elevated levels of growth hormones, raised cortisol levels, changes in the peripheral metabolism of thyroid hormone and abnormalities of insulin secretion".

If onset is before puberty, that development is delayed or arrested.

[edit] Presentation

There are a number of features, that although not necessarily diagnostic of anorexia, have been found to be commonly (but not exclusively) present in those with this eating disorder.[3][1]

[edit] Physical

Anorexia nervosa can put a serious strain on many of the body's organs and physiological resources,[4][5][6] 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,[7] 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.[4]

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.[8] 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.[9]

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