In general, eating disorders develop over time, sometimes over years, and often at a point when life brings fear and insecurity.
Anorexia nervosa is an illness in which people keep their body weight low by dieting, vomiting, or excessively exercising. The illness is caused by an anxiety about body shape and weight that originates from a fear of being fat or from wanting to be thin. How people with anorexia nervosa see themselves is often at odds with how they are seen by others, and they will usually challenge the idea that they should gain weight. People with anorexia nervosa can see their weight loss as a positive achievement that can help increase their confidence and self esteem. It can also contribute to a feeling of gaining control over body weight and shape.
Anorexia nervosa is, however, a serious condition that can cause severe physical problems because of the effects of starvation on the body. This can lead to loss of muscle strength and reduced bone strength in women and girls; in older girls and women their periods often stop. Men can suffer from a lack of interest in sex or impotency. The illness can affect people’s relationship with family and friends, causing them to withdraw; it can also have an impact on how they perform at school or in the workplace. The seriousness of the physical and emotional consequences of the condition is often not acknowledged or recognised, and people with anorexia nervosa often do not seek help.
Bulimia nervosa is an illness in which people feel that they have lost control over their eating. As in anorexia nervosa, they evaluate themselves according to their body shape and weight. Indeed in some instances (although not all), bulimia nervosa develops out of anorexia nervosa. People with bulimia nervosa are caught in a cycle of eating large quantities of food (called ‘binge eating’), and then vomiting, taking laxatives and diuretics (called ‘purging’), or excessive exercising and fasting, in order to prevent gaining weight. This behaviour can dominate daily life, and lead to difficulties in relationships and social situations. Usually people hide this behaviour from others, and their weight is often normal. People with bulimia nervosa tend not to seek help or support very readily.
People with bulimia nervosa can experience swings in their mood, and feel anxious and tense. They may also have very low self-esteem, and might try to hurt themselves by scratching or cutting. They may experience symptoms such as tiredness, feeling bloated, constipation, abdominal pain, irregular periods, or occasional swelling of the hands and feet. Excessive vomiting can cause problems with the teeth, while laxative misuse can seriously affect the heart.
Atypical eating disorders
Atypical eating disorders including binge eating disorder may affect more than half of people with an eating disorder. These conditions are called ‘atypical’ eating disorders because they do not exactly fit the description of either anorexia nervosa or bulimia nervosa. People might have some of the symptoms of anorexia nervosa and bulimia nervosa (such as dieting, binge eating, vomiting, and a preoccupation with food), but not all; or they might have symptoms that fall between anorexia nervosa and bulimia nervosa; or they might move from one set of problems to another over time. Many people with an atypical eating disorder have suffered with anorexia nervosa or bulimia nervosa in the past.
Of the atypical eating disorders, most is known about the treatment of binge eating disorder (BED). With BED, people have episodes of binge eating, but do not try to control their weight by purging. A person with BED may feel anxious and tense, and their condition might have an effect on their social life and relationships.
Extract from 'Understanding NICE guidance - a guide for people with eating disorders, their advocates and carers, and the public'.
More information about eating disorders
For information about medications prescribed to treat eating disorders see the trust's Choice and Medication website.