People with anorexia also report inability to distinguish emotions from bodily sensations in general, called alexithymia. Other psychological issues may factor into anorexia nervosa; some fulfill the criteria for a separate Axis I diagnosis or a personality disorder which is coded Axis II and thus are considered comorbid to the diagnosed eating disorder. Some people have a previous disorder which may increase their vulnerability to developing an eating disorder and some develop them afterwards.
Autism spectrum disorders occur more commonly among people with eating disorders than in the general population. There is evidence for biological, psychological, developmental, and sociocultural risk factors, but the exact cause of eating disorders is unknown. Anorexia nervosa is highly heritable. Consistent associations have been identified for polymorphisms associated with agouti-related peptide , brain derived neurotrophic factor , catechol-o-methyl transferase , SK3 and opioid receptor delta Obstetric complications: prenatal and perinatal complications may factor into the development of anorexia nervosa, such as maternal anemia , diabetes mellitus , preeclampsia , placental infarction , and neonatal cardiac abnormalities.
Neonatal complications may also have an influence on harm avoidance , one of the personality traits associated with the development of AN. Neuroendocrine dysregulation: altered signalling of peptides that facilitate communication between the gut, brain and adipose tissue, such as ghrelin , leptin , neuropeptide Y and orexin , may contribute to the pathogenesis of anorexia nervosa by disrupting regulation of hunger and satiety. Gastrointestinal diseases : people with gastrointestinal disorders may be more risk of developing disorders eating practices than the general population, principally restrictive eating disturbances.
Some authors report that unresolved symptoms prior to gastrointestinal disease diagnosis may create a food aversion in these persons, causing alterations to their eating patterns. Other authors report that greater symptoms throughout their diagnosis led to greater risk. It has been documented that some people with celiac disease, irritable bowel syndrome or inflammatory bowel disease who are not conscious about the importance of strictly following their diet, choose to consume their trigger foods to promote weight loss.
On the other hand, individuals with good dietary management may develop anxiety, food aversion and eating disorders because of concerns around cross contamination of their foods. Studies have hypothesized the continuance of disordered eating patterns may be epiphenomena of starvation. The results of the Minnesota Starvation Experiment showed normal controls exhibit many of the behavioral patterns of anorexia nervosa AN when subjected to starvation.
This may be due to the numerous changes in the neuroendocrine system , which results in a self-perpetuating cycle.
Anorexia nervosa is more likely to occur in a person's pubertal years. Some explanatory hypotheses for the rising prevalence of eating disorders in adolescence are "increase of adipose tissue in girls, hormonal changes of puberty, societal expectations of increased independence and autonomy that are particularly difficult for anorexic adolescents to meet; [and] increased influence of the peer group and its values. Early theories of the cause of anorexia linked it to childhood sexual abuse or dysfunctional families;   evidence is conflicting, and well-designed research is needed.
Anorexia nervosa has been increasingly diagnosed since ;  the increase has been linked to vulnerability and internalization of body ideals. Constant exposure to media that presents body ideals may constitute a risk factor for body dissatisfaction and anorexia nervosa. The cultural ideal for body shape for men versus women continues to favor slender women and athletic, V-shaped muscular men.
A review found that, of the magazines most popular among people aged 18 to 24 years, those read by men, unlike those read by women, were more likely to feature ads and articles on shape than on diet. Websites that stress the importance of attainment of body ideals extol and promote anorexia nervosa through the use of religious metaphors, lifestyle descriptions, "thinspiration" or "fitspiration" inspirational photo galleries and quotes that aim to serve as motivators for attainment of body ideals.
The media portray a false view of what people truly look like.
People then strive to look like these "perfect" role models when in reality they aren't near perfection themselves. Evidence from physiological, pharmacological and neuroimaging studies suggest serotonin may play a role in anorexia.
While acutely ill, metabolic changes may produce a number of biological findings in people with anorexia that are not necessarily causative of the anorexic behavior. For example, abnormal hormonal responses to challenges with serotonergic agents have been observed during acute illness, but not recovery. Nevertheless, increased cerebrospinal fluid concentrations of 5-Hydroxyindoleacetic acid a metabolite of serotonin , and changes in anorectic behavior in response to tryptophan depletion a metabolic precursor to serotonin support a role in anorexia.
The binding potential of 5-HT 2A receptors and 5-HT 1A receptors have been reportedly decreased and increased respectively in a number of cortical regions. While these findings may be confounded by comorbid psychiatric disorders, taken as a whole they indicate serotonin in anorexia. Neuroimaging studies investigating the functional connectivity between brain regions have observed a number of alterations in networks related to cognitive control, introspection, and sensory function. Alterations in networks related to the dorsal anterior cingulate cortex may be related to excessive cognitive control of eating related behaviors.
Similarly, altered somatosensory integration and introspection may relate to abnormal body image. Compared to controls, recovered anorexics show reduced activation in the reward system in response to food, and reduced correlation between self reported liking of a sugary drink and activity in the striatum and ACC. Increased binding potential of [11C]raclopride in the striatum, interpreted as reflecting decreased endogenous dopamine due to competitive displacement, has also been observed.
Structural neuroimaging studies have found global reductions in both gray matter and white matter, as well as increased cerebrospinal fluid volumes. Regional decreases in the left hypothalamus , left inferior parietal lobe , right lentiform nucleus and right caudate have also been reported  in acutely ill patients.
Bones muscles and joints Bones muscles and joints. Foods from plants and animals Some of the foods we eat come from animals and others come from plants Environmental health. These changes are characteristic of the euthyroid sick syndrome and, similar to the cardiac changes, represent an adaptive mechanism; hormonal replacement is not necessary. For example, if your symptoms are most like anorexia, your treatment will be similar to the treatment for anorexia. People with an eating disorder are often secretive and defensive about their eating and their weight, and they may deny being unwell.
However, these alterations seem to be associated with acute malnutrition and largely reversible with weight restoration, at least in nonchronic cases in younger people. Reduced white matter integrity in the fornix has also been reported. A diagnostic assessment includes the person's current circumstances, biographical history, current symptoms, and family history. The assessment also includes a mental state examination , which is an assessment of the person's current mood and thought content, focusing on views on weight and patterns of eating.
There are two subtypes of AN:  . The DSM-5 states these as follows: . Medical tests to check for signs of physical deterioration in anorexia nervosa may be performed by a general physician or psychiatrist, including:. A variety of medical and psychological conditions have been misdiagnosed as anorexia nervosa; in some cases the correct diagnosis was not made for more than ten years.
The distinction between the diagnoses of anorexia nervosa, bulimia nervosa and eating disorder not otherwise specified EDNOS is often difficult to make as there is considerable overlap between people diagnosed with these conditions. Seemingly minor changes in people's overall behavior or attitude can change a diagnosis from anorexia: binge-eating type to bulimia nervosa.
A main factor differentiating binge-purge anorexia from bulimia is the gap in physical weight. Someone with bulimia nervosa is ordinarily at a healthy weight, or slightly overweight. Someone with binge-purge anorexia is commonly underweight. There is no conclusive evidence that any particular treatment for anorexia nervosa works better than others; however, there is enough evidence to suggest that early intervention and treatment are more effective.
Although restoring the person's weight is the primary task at hand, optimal treatment also includes and monitors behavioral change in the individual as well. Psychotherapy for individuals with AN is challenging as they may value being thin and may seek to maintain control and resist change. Initially developing a desire to change is important. Diet is the most essential factor to work on in people with anorexia nervosa, and must be tailored to each person's needs. Food variety is important when establishing meal plans as well as foods that are higher in energy density. Family-based treatment FBT has been shown to be more successful than individual therapy for adolescents with AN.
There is tentative evidence that family therapy is as effective as treatment as usual and it is unclear if family therapy is more effective than educational interventions. Cognitive behavioral therapy CBT is useful in adolescents and adults with anorexia nervosa;  acceptance and commitment therapy is a type of CBT, which has shown promise in the treatment of AN. Pharmaceuticals have limited benefit for anorexia itself. AN has a high mortality  and patients admitted in a severely ill state to medical units are at particularly high risk. Diagnosis can be challenging, risk assessment may not be performed accurately, consent and the need for compulsion may not be assessed appropriately, refeeding syndrome may be missed or poorly treated and the behavioural and family problems in AN may be missed or poorly managed.
The rate of refeeding can be difficult to establish, because the fear of refeeding syndrome RFS can lead to underfeeding. It is thought that RFS, with falling phosphate and potassium levels, is more likely to occur when BMI is very low, and when medical comorbidities such as infection or cardiac failure, are present.
In those circumstances, it is recommended to start refeeding slowly but to build up rapidly as long as RFS does not occur. AN has the highest mortality rate of any psychological disorder. Alexithymia influences treatment outcome. According to the Morgan-Russell criteria, individuals can have a good, intermediate, or poor outcome. The good outcome also excludes psychological health. Recovery for people with anorexia nervosa is undeniably positive, but recovery does not mean a return to normal.
Anorexia nervosa can have serious implications if its duration and severity are significant and if onset occurs before the completion of growth, pubertal maturation, or the attainment of peak bone mass. In such cases, provided that growth potential is preserved, height increase can resume and reach full potential after normal intake is resumed. Anorexia nervosa causes alterations in the female reproductive system; significant weight loss, as well as psychological stress and intense exercise, typically results in a cessation of menstruation in women who are past puberty.
In patients with anorexia nervosa, there is a reduction of the secretion of gonadotropin releasing hormone in the central nervous system, preventing ovulation. Both height gain and pubertal development are dependent on the release of growth hormone and gonadotrophins LH and FSH from the pituitary gland. Suppression of gonadotrophins in people with anorexia nervosa has been documented.
Buildup of bone is greatest during adolescence, and if onset of anorexia nervosa occurs during this time and stalls puberty, low bone mass may be permanent.
Hepatic steatosis, or fatty infiltration of the liver, can also occur, and is an indicator of malnutrition in children. Wernicke encephalopathy , which results from vitamin B1 deficiency , has been reported in patients who are extremely malnourished; symptoms include confusion, problems with the muscles responsible for eye movements and abnormalities in walking gait.
The most common gastrointestinal complications of anorexia nervosa are delayed stomach emptying and constipation , but also include elevated liver function tests , diarrhea , acute pancreatitis , heartburn , difficulty swallowing , and, rarely, superior mesenteric artery syndrome. Other symptoms of gastroparesis include early satiety, fullness, nausea, and vomiting. The symptoms may inhibit efforts at eating and recovery, but can be managed by limiting high-fiber foods, using liquid nutritional supplements, or using metoclopramide to increase emptying of food from the stomach.
Anorexia nervosa increases the risk of sudden cardiac death , though the precise cause is unknown. Cardiac complications include structural and functional changes to the heart. Cardiac complications can include arrhythmias , abnormally slow heart beat , low blood pressure , decreased size of the heart muscle, reduced heart volume, mitral valve prolapse , myocardial fibrosis , and pericardial effusion. Abnormalities in conduction and repolarization of the heart that can result from anorexia nervosa include QT prolongation , increased QT dispersion , conduction delays, and junctional escape rhythms.
Hypokalemia most commonly results in anorexic patients when restricting is accompanied by purging induced vomiting or laxative use.
Hypotension low blood pressure is common, and symptoms include fatigue and weakness. Orthostatic hypotension, a marked decrease in blood pressure when standing from a supine position, may also occur. Symptoms include lightheadedness upon standing, weakness, and cognitive impairment, and may result in fainting or near-fainting. The weight loss in anorexia nervosa also causes atrophy of cardiac muscle.