What are Anorexia nervosa, its causes and its symptoms?

Anorexia nervosa is an eating disorder characterised by restricted food intake and significant weight loss. Those affected are primarily women (10 for every man) and have a distorted perception of their own body, making them look fat even when their weight is below the recommended. For this reason, they begin a progressive weight loss through fasting, drastically reducing the amount of food and intense physical exercise.

Usually, the disorder begins with the elimination of carbohydrates since there is a false belief that they are fattening. The rejection of fats, proteins and even liquids follows, leading to cases of extreme dehydration. These drastic measures can be added to other risk behaviours such as diuretics, laxatives, purging and provoking vomiting. In addition, affected people can lose from 15% to 50% (in the most critical cases) of their body weight. This disease is usually related to serious psychological disorders that cause changes in behaviour, emotional behaviour and stigmatisation of the body.

Noelia Olmo, an assistant psychiatrist at the Unit for Eating Behavior Disorders at the University Hospital of Álava, points out that it is estimated that around ” 20% of patients with eating behaviour disorders will make a suicide attempt “.

The maintenance of the risk behaviours of anorexia nervosa can lead to cardiovascular, hepatic, metabolic and bone complications.


The ultimate cause of anorexia nervosa is unknown, but social factors seem to play a role. Ana González Pinto, president of the Spanish Foundation for Psychiatry and Mental Health (Fepsm) and head of the Psychiatry Service at the Álava University Hospital, points out that this disorder has biopsychosocial causality: “It has to do, on the one hand, with the biology of the person (the tendency to be one way or another and the predisposition to certain diseases); the psychology (the personality, the way of reacting to problems) and the social part, which is especially important for mental health”.

Taking this multifactorial origin into account, these are some of the most relevant risk factors:

  • To be a woman.
  • Having a family history of eating disorders.
  • Obesity ( own or maternal).
  • Living with a family member who is overweight, obese or diabetic is constantly on a diet.
  • Practising a sport or activity with a great demand regarding weight and physical appearances, such as rhythmic gymnastics or ballet.
  • Stressful life events or traumatic events, such as the loss of a loved one or separation from parents.
  • Away from home.
  • School failure.


This pathology is characterised by a significant weight loss caused by the patient and erroneous perception of one’s body. Consequently, endocrine problems become apparent in a relatively short space of time. The main symptoms of this disease that determine the appearance of the disease are the following:

  • Difficult to maintain body weight above the appropriate minimum for the age and size of the patient.
  • Patients fear weight gain or obesity even when the weight is below recommended.
  • Distorted perception of the body, weight and proportions.
  • Missing of three consecutive menstrual cycles in women ( amenorrhea ).

Anorexics can experience various symptoms: vomiting, constipation, amenorrhea, abdominal pain etc.

But it is the family that detects the symptoms that sound the alarm:

  • Excessive concern about the caloric composition of food and food preparation.
  • Constant feeling of cold.
  • Progressive reduction of food.
  • Obsession with images, the scale, studies and sports.
  • Use traps to avoid food.
  • hyperactivity

Other typical features of these symptoms include irritability, depression and emotional or personality disorders. Likewise, an alteration of the sensation of satiety and fullness before meals, nausea, swelling, or even absence of sensations is manifested. Most of the cognitive disorders that focus on food, body weight and physical appearance are also observed in this pathology:

  • Selective abstractions.
  • Selective use of information.
  • Generalisations.
  • Superstitions.
  • The negative side of any situation is magnified.
  • Dichotomous thinking.
  • Self-referential ideas.
  • Arbitrary inference.

As for the clinical consequences, the possible symptoms are very varied:

  • Reduced heart rate.
  • Arrhythmias can lead to cardiac arrest.
  • Lower blood pressure.
  • Menstruation stops in women ( amenorrhoea ).
  • Bone mass decreases, and, in very early cases, the growth rate slows down.
  • Decreased intestinal motility.
  • Anaemia.
  • Long, fine hair, called woolly, appears on the back, thighs, forearms, cheeks and neck.
  • Chronic constipation.
  • The decrease in energy expenditure produces a constant sensation of cold.
  • The skin becomes dehydrated, dry and cracked.
  • Turing Yellowing of the palms of the hands and the soles of the feet due to the deposition of carotenoids in the sebaceous glands.
  • Nails break.
  • Hair loss.
  • Problems with teeth and peripheral oedema, bloating and abdominal pain.