What are the symptoms of anorexia nervosa?

• distorted body image and intense, persistent fear of gaining weight
• excessive weight loss
• menstrual irregularities
• excessive body/facial hair
• compulsive exercise

• low body weight (less than 85 percent of normal weight for height and age)
• intense fear of becoming obese, even as individual is losing weight
• distorted view of one's body weight, size, or shape; sees self as too fat, even when very underweight; expresses feeling fat, even when very thin
• refuses to maintain minimum normal body weight
• in females, absence of three menstrual cycles without another cause
• excessive physical activity
• denies feelings of hunger
• preoccupation with food preparation
• bizarre eating behaviors

• dry skin that when pinched and released, stays pinched
• dehydration
• abdominal pain
• constipation
• lethargy
• fatigue
• intolerance to cold temperatures
• emaciation
• development of lanugo (fine, downy body hair) yellowing of the skin

• Eat tiny portions, refuse to eat or deny they are hungry
• Show abnormal weight loss - as much as 15 percent or more of their body weight
• Be hyperactive, depressed, moody or insecure
• Exercise excessively and compulsively.

Some of the early signs of anorexia nervosa are:

• perfectionism, striving for control
• a preoccupation with weight 
• an obsessive increase in activity or exercise
• a drastic reduction in food and drink
• an unusual focus on food, recipes, or preparing food for others 

Over time, this can lead to extreme weight loss, social isolation, and denial of the problem. As the malnourishment progresses, all body systems are affected. In addition to the weight loss, some of the ongoing signs of anorexia nervosa are:

• skin becomes pale and less elastic
• loss of muscle tone
• fatigue
• hair loss 
• loss of tooth enamel
• heart problems
• loss of regular menstrual cycle

Someone with anorexia may look very thin. She or he may use extreme measures to lose weight by:

• Making her or himself throw up
• Taking pills to urinate or have a bowel movement
• Taking diet pills
• Not eating or eating very little
• Exercising a lot, even in bad weather or when hurt or tired
• Weighing food and counting calories
• Eating very small amounts of only certain foods
• Moving food around the plate instead of eating it

Someone with anorexia may also have a distorted body image, shown by thinking she or he is fat, wearing baggy clothes, weighing her or himself many times a day, and fearing weight gain.

Anorexia can also cause someone to not act like her or himself. She or he may talk about weight and food all the time, not eat in front of others, be moody or sad, or not want to go out with friends. People with anorexia may also have other psychiatric and physical illnesses, including:

• Depression
• Anxiety
• Obsessive behavior
• Substance abuse
• Issues with the heart and/or brain
• Problems with physical development

This answer is based on source information from the National Women's Health Information Center.

Anorexia nervosa is a severe, life-threatening eating disorder. Sufferers are at least 15 percent below normal weight, are terrified of gaining an ounce, and obsess about their body shape and size. Other symptoms can include:

• Missed periods
• Fatigue
• Depression
• Lack of interest in school, friends, or activities
• Preoccupation with food (preparing it, counting calories, but not eating it)
• Secretive, self-induced vomiting (including use of syrup of ipecac)
• Laxative use
• Excessive exercising
• Anxiety at mealtimes
• Anemia
• Insomnia

One in ten people who battle anorexia die from severe weight loss, a weakened heart, or suicide. Survivors may suffer bone loss, infertility, and many other serious consequences.

From The Smart Parent's Guide: Getting Your Kids Through Checkups, Illnesses, and Accidents by Jennifer Trachtenberg.

Anorexia nervosa is a severe psychiatric disorder characterized by prolonged starvation, which results in low weight. Clinicians generally define low weight as a body mass index of less than 18.5 or an equivalent cutoff in adolescents. People with anorexia nervosa often engage in obsessive or compulsive rituals to avoid food such as calorie counting, cutting food into tiny pieces, or excessive exercise. They typically experience intense feelings of disgust and fear in situations when food is presented or eating is common, and in situations where they perceive their body or eating habits are under evaluation. Depression and anxiety, particularly obsessive-compulsive disorder, commonly co-occur with the disorder. In addition, low weight can cause serious medical complications including bone loss, weakening of the heart muscle, and loss of menstruation in women. The disorder affects primarily women and generally begins in adolescence.