Anorexia nervosa, commonly called anorexia, is a severe eating disorder in which affected individuals have a highly distorted body image. Although they are already significantly underweight, they perceive themselves as too fat and try to reduce their weight further. This exaggerated fear of gaining weight leads sufferers to drastically restrict their food intake or to purge after eating in order to get rid of the food quickly.
There are two main forms of anorexia nervosa: in the restrictive form, individuals consume very little food and often engage in excessive exercise. In the second form, known as the binge-eating/purging type, recurrent binge episodes occur during which large amounts of food are consumed and then expelled through vomiting or laxatives.
This eating disorder is not only a psychological illness but can also have massive physical consequences, since extremely low food intake can cause severe damage to organs such as the heart, liver and kidneys. Weight is typically at least 15 percent below the normal weight for the individual's height and developmental stage. In adults this often corresponds to a body mass index (BMI) below 17.5.
Anorexia occurs particularly frequently in women between 12 and 35 years of age and can be promoted by external factors such as occupations (e.g. dancers, models) or certain personality traits (e.g. perfectionism, low self-esteem). People with high performance demands and a strong need for control are also especially at risk.
Anorexia nervosa initially manifests as an intense preoccupation with one's body weight and diet, even when the person is not overweight. A growing fixation on weight control develops, with the individual continuing to feel too fat despite obvious weight loss. Weight loss is often downplayed or even denied. Warnings from friends or relatives are ignored and any weight gain is regarded as a personal failure.
People with anorexia often have noticeable eating habits: they count calories, spend a lot of time on recipes and prepare elaborate meals for others without eating them themselves. Some hoard or hide food or throw it away secretly. A portion of sufferers also tend to have binge episodes and then induce vomiting, take laxatives or diuretics to reduce weight further.
Typical physical symptoms include the absence of menstruation in women, a slowed heart rate, low blood pressure and a low body temperature. Patients also often develop fine body hair and swelling due to water retention may occur. Depressive moods are common and there are hormonal changes such as a decrease in sex hormones and an increase in cortisol levels.
Even with severe underweight, many people remain physically active and exercise excessively to maintain weight loss. Severe deficiencies typically appear only in advanced stages. With prolonged undernutrition nearly all organ systems are affected: bone density decreases, the risk of osteoporosis increases, and heart function and electrolyte balance are disrupted. This can lead to life-threatening heart rhythm disturbances and dehydration that can, in extreme cases, be fatal.
The causes of anorexia are extremely complex and cannot be reduced to a single factor. Rather, the illness arises from an interplay of biological, psychological and sociocultural influences that can reinforce each other.
Biological factors contribute significantly to the development of anorexia. Impaired stress processing is one possible cause. This may be genetically determined or shaped by prenatal influences and early life experiences. Research also points to a genetic predisposition, as the illness appears more frequently in some families. A disturbed neurotransmitter metabolism in the brain is characteristic, particularly elevated serotonin levels that influence eating behaviour. Serotonin increases feelings of satiety and can further inhibit food intake, favouring dietary restriction.
Other common causes are psychological factors, such as the desire to control one's body and life. Many people with anorexia strive for perfection and display a high degree of discipline that they express through strict weight control. It is often an attempt to cope with inner conflicts or to process traumatic experiences. The onset of puberty with its bodily and hormonal changes is also a risk factor.
Furthermore, high performance expectations prevalent in many middle- and upper-class families favour the development of the disorder. Those affected are often very intelligent, perfectionistic and self-critical. These internal demands are reinforced by societal ideals that portray slim bodies as desirable. Low self-esteem is often characteristic and control over eating initially provides a sense of security and achievement, which in turn supports the disordered behaviour.
Sociocultural influences, such as the Western beauty ideal that presents extremely thin bodies as attractive, also exert great pressure. This causes many adolescents, particularly girls, to feel dissatisfied with their bodies. Constant exposure to unnaturally thin role models leads them to develop a distorted idea of what a healthy body should look like. Criticism of one's appearance, teasing or negative remarks about weight can act as triggers for anorexia in this context.
Anorexia and bulimia are two common eating disorders that are often confused because they share some features but also differ significantly. Both disorders are characterised by a distorted body perception and a strong need to control eating behaviour. Patients often perceive themselves as too fat even though they are underweight or have a normal weight.
Anorexia is characterised by extreme underweight and strict calorie counting, with sufferers starving themselves to lose weight. Bulimia, on the other hand, involves repeated binge-eating episodes followed by compensatory measures such as vomiting or excessive exercise to offset the calories consumed. While anorexia often leads to marked underweight, people with bulimia nervosa are generally not extremely underweight and may have a normal weight.
The effectiveness of anorexia treatment depends strongly on individual tailoring of therapy. Central elements of treatment are normalising body weight, establishing regular eating behaviour, and treating physical complications. Psychotherapeutic approaches such as cognitive behavioural therapy or systemic family therapy help patients understand and manage their feelings and behavioural patterns. These therapies aim to reduce the symptoms of the eating disorder as well as any accompanying psychological problems.
Another important aspect of therapy is relapse prevention. It can be helpful to involve relatives in the treatment process. Nutritional counselling also plays an important role in promoting a balanced diet.
In severe cases, especially with rapid weight loss, severe underweight or lack of weight gain despite outpatient therapy, inpatient care may be necessary. Inpatient treatment is guided by the patient's current health status and addresses both physical and psychological aspects to support holistic recovery.
Anorexia is a serious illness that has both physical and psychological consequences. It is necessary to accompany affected people with empathy and understanding to encourage positive change and help them develop a healthy relationship with food and their body.


