Anorexia Nervosa: Symptoms, Causes, and Treatment


What is Anorexia Nervosa?

Anorexia nervosa is an eating disorder characterized by weight loss (or lack of appropriate weight gain in growing children); difficulties maintaining an appropriate body weight for height, age, and stature; and, in many individuals, distorted body image. Nearly 1 in every 100 American women will experience anorexia at some time.

As per DSM-5, “There are three essential features of anorexia nervosa: (1) Persistent energy intake restriction; (2) Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain; and (3) A disturbance in self-perceived weight or shape.” (American Psychiatric Association, 2013) A person with anorexia places a high value on controlling his/her weight and shape, using extreme efforts that tend to significantly interfere with his/her life.

Picture showing a thing woman seeing her reflection in a mirror as being obese
Distorted self-perception of body image

Anorexics usually severely restrict the amount of food they eat in an attempt to prevent weight gain or to continue losing weight. The individual will try to maintain a bodyweight of 85% or less of their expected weight. They may restrict calorie intake by vomiting after eating or by abusing laxatives, diuretics, enemas, or diet aids. They may even exercise in excess in an attempt to lose weight. Even if they lose weight to a significant extent, they continue to fear weight gain (Mayo Clinic Staff, 2018).

Because anorexics equate thinness with self-worth, they resort to these steps. So, it is more a way of coping with emotional problems. But, the sad fact is that it can sometimes be life-threatening. Although it is difficult to come to normalcy in this eating disorder, with treatment people do get better and are able to eat healthier.

Symptoms of Anorexia Nervosa (Mayo Clinic Staff, 2018) (National Eating Disorders Association, n.d.)

In anorexia, the body is denied the essential nutrients, so it is forced to slow down all of its processes to conserve energy, resulting in serious medical consequences. The body is generally resilient, and laboratory tests can generally appear normal even as someone is at high risk of death.

Physical Signs and Symptoms

Physical signs and symptoms of anorexia include:

  • Extreme weight loss or not making expected developmental weight gains
  • Thin appearance
  • Abnormal laboratory findings (anemia, low thyroid and hormone levels, low potassium, low blood cell counts, slow heart rate)
  • Stomach cramps, other non-specific gastrointestinal complaints (constipation, acid reflux, etc.)
  • Difficulties concentrating
  • Fatigue
  • Insomnia
  • Dizziness or fainting
  • Feeling cold all the time
  • Menstrual irregularities—amenorrhea, irregular periods or only having a period while on hormonal contraceptives (this is not considered a “true” period)
  • Cuts and calluses across the top of finger joints (a result of inducing vomiting)
  • Cavities, or discoloration of teeth, from vomiting
  • Dental problems, such as enamel erosion, cavities, and tooth sensitivity
  • Thinning of hair on the head, dry and brittle hair 
  • Fine hair on the body
  • Dry skin
  • Yellow skin (in context of eating large amounts of carrots)
  • Muscle weakness
  • Irregular heart rhythms
  • Low blood pressure
  • Dehydration
  • Swelling of arms or legs

Emotional and Behavioral Symptoms

Behavioral symptoms of anorexia may include attempts to lose weight by:

  • Dieting or fasting
  • Maintaining an excessive, rigid exercise regimen – despite weather, fatigue, illness, or injury 
  • Bingeing and self-induced vomiting

Emotional and behavioral signs and symptoms may include:

  • Resists or is unable to maintain a bodyweight appropriate for their age, height, and build 
  • Makes frequent comments about feeling “fat” or overweight despite weight loss
  • Cooks meals for others without eating
  • Frequently skipping meals or refusing to eat
  • Refuses to eat certain foods (e.g., no carbohydrates, etc.), eating only a few certain “safe” foods, usually those low in fat and calories
  • Denial of hunger or making excuses for not eating
  • Develops food rituals (e.g., eating foods in certain orders, excessive chewing, rearranging food on a plate)
  • Seems concerned about eating in public
  • Lying about how much food has been eaten
  • Complains of constipation, abdominal pain, cold intolerance, lethargy, and/or excess energy
  • Has an intense fear of weight gain or being “fat,” even though underweight and may repeatedly weigh or measure the body
  • Frequent checking in the mirror for perceived flaws
  • Complaining about being fat or having parts of the body that are fat
  • Dresses in layers to hide weight loss or stay warm
  • Flat mood (lack of emotion), has limited social spontaneity
  • Withdraws from usual friends and activities and becomes more isolated, withdrawn, and secretive
  • Shows inflexible thinking
  • Irritability
  • Postpuberty female loses menstrual period
  • Insomnia
  • Reduced interest in sex

Causes of Anorexia Nervosa (Mayo Clinic Staff, 2018) (Sadock, et al., 2017)

Anorexia is more common in girls and women, teenagers, and those under 40 years of age. The exact cause of anorexia is not known.

  • Genetic and Biological Factors. Individuals with a family history of anorexia nervosa are much more likely than those with no family history to receive a diagnosis during their lifetime. Risk is also increased if a relative has a history of a different eating disorder. Finally, once the illness sets in, the biological and psychological changes to the body that occur in the starvation state, including low mood and increased obsessionality, may help to maintain the illness.
  • Psychological. Certain personality traits including high levels of perfectionism, self-discipline, harm-avoidance, and self-criticism are common in individuals with the illness. Some people with anorexia may have obsessive-compulsive personality traits that make it easier to stick to strict diets and forgo food despite being hungry. They may have an extreme drive for perfectionism, which causes them to think they’re never thin enough. And they may have high levels of anxiety and engage in restrictive eating to reduce it.
  • Environmental. The cultural ideal of thinness, which is certainly perpetuated by the media, may fuel the overvaluation of shape and weight. Peer pressure may help fuel the desire to be thin, particularly among young girls. Participation in certain activities in which weight is emphasized may increase the probability of developing anorexia nervosa or another eating disorder. Ballet, gymnastics, modeling, and weight-restricted sports like wrestling or light-weight rowing may lead to preoccupation with body form and unhealthy attempts to control weight.
  • Emotional Stress. Anything which increases emotional stress increases the risk of anorexia, such as joining a new school or job; a relationship breakup; or the death or illness of a loved one.

Diagnosis of Anorexia Nervosa

Body mass index (BMI; calculated as weight in kilograms/height in meters2) is a useful measure to assess body weight for height. The DSM-5 criteria for a diagnosis of Anorexia Nervosa require the individual to be significantly underweight for age and height. Although it is not possible to set a single weight loss standard that applies equally to all individuals, DSM-5 notes that a BMI of 18.5 is the lower limit of normal for adults per the recommendation of the US Centers for Disease Control and Prevention (CDC) (Tasman, et al., 2015).

For children and adolescents, determining a BMI-for-age percentile is useful. The CDC has used a BMI-for-age below the 5th percentile as suggesting underweight; however, children and adolescents with a BMI above this benchmark may be judged to be significantly underweight in light of the failure to maintain their expected growth trajectory (American Psychiatric Association, 2013).

If your doctor suspects that you have anorexia nervosa, he or she will try to rule out medical causes for the weight loss, and check for any related complications.

These exams and tests generally include (Mayo Clinic Staff, 2018):

  • Physical exam.Measuring your height and weight; checking your vital signs; checking your skin and nails for problems; listening to your heart and lungs; and examining your abdomen.
  • Lab tests.Blood tests to check blood counts, electrolytes and protein as well as the functioning of your liver, kidney, and thyroid. A urinalysis also may be done.
  • Psychological evaluation.A doctor will ask about your thoughts, feelings and eating habits. You may need to complete psychological self-assessment questionnaires.
  • X-rays.X-rays may be taken to check for bone density or check for pneumonia or heart problems.

In addition, your doctor may also use the DSM-5 criteria for anorexia nervosa.

Treatment of Anorexia Nervosa (Tasman, et al., 2015) (Brazier, 2018) (Mayo Clinic Staff, 2018)

The goals of treatment are:

  • To engage the patient and their family, which can be challenging. Patients usually minimize their symptoms and suggest that the concerns of the family and friends, who have often been instrumental in arranging the consultation, are greatly exaggerated. It is helpful to identify a problem that the patient can acknowledge, such as weakness, irritability, difficulty concentrating, or trouble with binge-eating. The clinician may then attempt to educate the patient regarding the pervasive physical and psychological effects of semi-starvation and about the need for weight gain if the acknowledged problem is to be successfully addressed.
  • To assess and address acute medical problems, such as fluid and electrolyte disturbances and cardiac arrhythmias.
  • To restore body weight to a healthy level
  • To treat emotional problems, including low self-esteem
  • To address distorted thinking
  • To help the patient develop behavioral changes that will persist in the long term
  • To prevent relapse.


Counseling includes cognitive-behavioral therapy (CBT), which focuses on changing the way the person thinks about food and body weight and responds to stressful or difficult situations.

Nutrition counseling aims to help the patient regain healthful eating habits. They learn about the role of a balanced diet in maintaining good health.

In teenagers, family-based therapy may be needed to mobilize parents to help their child with re-feeding and weight restoration until the child can make good choices about health.


No medication is FDA approved to treat it, but nutritional supplements may be needed, and the doctor may prescribe drugs to control any underlying problems, such as anxiety, obsessive-compulsive disorder (OCD), or depression.


Hospitalization may be needed if there is severe weight-loss or malnutrition, a persistent refusal to eat, and for such issues as a heart rhythm disturbance, dehydration, electrolyte imbalances or a psychiatric emergency. The intake of food will be increased gradually to enable safe weight gain.

Some clinics specialize in treating people with eating disorders. They may offer day programs or residential programs rather than full hospitalization.

A large percentage of patients with anorexia nervosa remain chronically ill; 30–50% of patients successfully treated in the hospital require rehospitalization within 1 year of discharge. They are at increased risk of relapse during periods of high stress or during triggering situations. Ongoing therapy or periodic appointments during times of stress may help you stay healthy.


American Psychiatric Association, 2013. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Washington, DC: American Psychiatric Publishing.

Brazier, Y., 2018. Anorexia nervosa: What you need to know. [Online]
Available at:
[Accessed 2 Nov 2019].

Mayo Clinic Staff, 2018. Anorexia Nervosa. [Online]
Available at:
[Accessed 2 Nov 2019].

National Eating Disorders Association, n.d. Anorexia Nervosa. [Online]
Available at:
[Accessed 2 Nov 2019].

Sadock, B. J., Sadock, V. A. & Ruiz, P., 2017. Kaplan and Sadock’s Comprehensive Textbook of Psychiatry. 10th ed. Philadelphia: Wolters Kluwer.

Tasman, A. et al. eds., 2015. Psychiatry. 4th ed. Oxford: Wiley Blackwell.


Anorexia Nervosa: Symptoms, Causes, and Treatment
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Anorexia Nervosa: Symptoms, Causes, and Treatment
Anorexia nervosa is an eating disorder characterized by weight loss; difficulties maintaining an appropriate body weight; and, distorted body image.
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