Anorexia  nervosa  is an eating disorder characterized by an abnormally low body weight, intense fear of gaining weight and a distorted perception of body weight. People with anorexia place a high value on controlling their weight and shape, using extreme efforts that tend to significantly interfere with activities in their lives.

To prevent weight gain or to continue losing weight, people with anorexia usually severely restrict the amount of food they eat. They may control calorie intake by vomiting after eating or by misusing laxatives, diet aids, diuretics or enemas. They may also try to lose weight by exercising excessively.

Some people with anorexia binge and purge, similar to individuals who have bulimia nervosa. However, people with anorexia generally struggle with an abnormally low body weight, while individuals with bulimia typically are normal to above normal weight. No matter how weight loss is achieved, the person with anorexia has an intense fear of gaining weight.

Anorexia isn’t really about food. It’s an unhealthy way to try to cope with emotional problems. When you have anorexia, you often equate thinness with self-worth.

Anorexia can be very difficult to overcome. But with treatment, you can gain a better sense of who you are, return to healthier eating habits and reverse some of anorexia’s serious complications.

Symptoms

The physical signs and symptoms of anorexia nervosa are related to starvation, but the disorder also includes emotional and behavior issues related to an unrealistic perception of body weight and an extremely strong fear of gaining weight or becoming fat.

Physical symptoms

Physical signs and symptoms of anorexia may include:

• Extreme weight loss
• Thin appearance
• Abnormal blood counts
• Fatigue
• Insomnia
• Dizziness or fainting
• Bluish discoloration of the fingers
• Hair that thins, breaks or falls out
• Soft, downy hair covering the body
• Absence of menstruation
• Constipation
• Dry or yellowish skin
• Intolerance of cold
• Irregular heart rhythms
• Low blood pressure
• Dehydration
• Osteoporosis
• Swelling of arms or legs

Emotional and behavioral symptoms

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

• Severely restricting food intake through dieting or fasting and may include excessive exercise
• Bingeing and self-induced vomiting to get rid of the food and may include use of laxatives, enemas, diet aids or herbal products

Other emotional and behavioral signs and symptoms related to anorexia may include:

• Preoccupation with food
• Refusal to eat
• Denial of hunger
• Fear of gaining weight
• Lying about how much food has been eaten
• Flat mood (lack of emotion)
• Social withdrawal
• Irritability
• Reduced interest in sex
• Depressed mood
• Thoughts of suicide

When to see a doctor

Anorexia, like other eating disorders, can take over your life. Unfortunately, many people with anorexia don’t want treatment, at least initially. Their desire to remain thin overrides concerns about their health. If you have a loved one you’re worried about, urge her or him to talk to a doctor.

If you’re experiencing any of the problems listed above, or if you think you may have an eating disorder, get help. If you’re hiding your anorexia from loved ones, try to find a confidant you can talk to about what’s going on.

Red flags to watch for

It may be hard to notice signs and symptoms of anorexia because people with anorexia often disguise their thinness, eating habits or physical problems.

If you’re concerned that a loved one may have anorexia, watch for these possible red flags:

• Skipping meals
• Making excuses for not eating
• Eating only a few certain “safe” foods, usually those low in fat and calories
• Adopting rigid meal or eating rituals, such as spitting food out after chewing
• Cooking elaborate meals for others but refusing to eat
• Repeated weighing or measuring of themselves
• Frequent checking in the mirror for perceived flaws
• Complaining about being fat
• Not wanting to eat in public
• Calluses on the knuckles and eroded teeth if inducing vomiting
• Covering up in layers of clothing

The exact cause of anorexia nervosa is unknown. As with many diseases, it’s probably a combination of biological, psychological and environmental factors.

• Biological. Although it’s not yet clear which genes are involved, there may be genetic changes that make some people more vulnerable to developing anorexia. Some people may have a genetic tendency toward perfectionism, sensitivity and perseverance — all traits associated with anorexia.
• Psychological. Some emotional characteristics may contribute to anorexia. Young women 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, causing them to think they’re never thin enough. They may have high levels of anxiety and restrict their eating to reduce it.
• Environmental. Modern Western culture emphasizes thinness. Success and worth are often equated with being thin. Peer pressure may help fuel the desire to be thin, particularly among young girls.

Risk factors

Certain risk factors increase the risk of anorexia nervosa, including:

• Being female. Anorexia is more common in girls and women. However, boys and men have been increasingly developing eating disorders, perhaps because of growing social pressures.
• Young age. Anorexia is more common among teenagers. Still, people of any age can develop this eating disorder, though it’s rare in those over 40. Teens may be more susceptible because of all the changes their bodies go through during puberty. They also may face increased peer pressure and be more sensitive to criticism or even casual comments about weight or body shape.
• Genetics. Changes in certain genes may make people more susceptible to anorexia.
• Family history. Those with a first-degree relative — a parent, sibling or child — who had the disease have a much higher risk of anorexia.
• Weight changes. When people change weight — on purpose or unintentionally — those changes may be reinforced by positive comments from others for losing weight or by negative remarks for gaining weight. Such changes and comments may trigger someone to start dieting to an extreme. In addition, starvation and weight loss may change the way the brain works in vulnerable individuals, which may perpetuate restrictive eating behaviors and make it difficult to return to normal eating habits.
• Transitions. Whether it’s a new school, home or job; a relationship breakup; or the death or illness of a loved one, change can bring emotional stress and increase the risk of anorexia.
• Sports, work and artistic activities. Athletes, actors, dancers and models are at higher risk of anorexia. Coaches and parents may inadvertently raise the risk by suggesting that young athletes lose weight.
• Media and society. The media, such as TV and fashion magazines, frequently feature a parade of skinny models and actors. These images may seem to equate thinness with success and popularity. But whether the media merely reflect social values or actually drive them isn’t clear-cut.

Complications

Anorexia nervosa can have numerous complications. At its most severe, it can be fatal. Death may occur suddenly — even when someone is not severely underweight. This may result from abnormal heart rhythms (arrhythmias) or an imbalance of electrolytes — minerals such as sodium, potassium and calcium that maintain the balance of fluids in your body.

Other complications of anorexia include:

• Anemia
• Heart problems, such as mitral valve prolapse, abnormal heart rhythms or heart failure
• Bone loss, increasing risk of fractures later in life
• In females, absence of a period
• In males, decreased testosterone
• Gastrointestinal problems, such as constipation, bloating or nausea
• Electrolyte abnormalities, such as low blood potassium, sodium and chloride
• Kidney problems
• Suicide

If a person with anorexia becomes severely malnourished, every organ in the body can be damaged, including the brain, heart and kidneys. This damage may not be fully reversible, even when the anorexia is under control.

In addition to the host of physical complications, people with anorexia also commonly have other mental disorders as well. They may include:

• Depression, anxiety and other mood disorders
• Personality disorders
• Obsessive-compulsive disorders
• Alcohol and substance misuse

Prevention

There’s no guaranteed way to prevent anorexia nervosa. Primary care physicians (pediatricians, family physicians and internists) may be in a good position to identify early indicators of anorexia and prevent the development of full-blown illness. For instance, they can ask questions about eating habits and satisfaction with appearance during routine medical appointments.

If you notice that a family member or friend has low self-esteem, severe dieting habits and dissatisfaction with appearance, consider talking to him or her about these issues. Although you may not be able to prevent an eating disorder from developing, you can talk about healthier behavior or treatment options.