How Anorexia Is Diagnosed

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Anorexia (also called anorexia nervosa) is a serious eating disorder involving dangerous weight loss or lack of appropriate weight gain, body image distortion, and anxiety surrounding food and eating.

While anorexia can cause serious health problems including death, it isn’t always easy to recognize, even by the people who have the disorder themselves.

Diagnostic tools exist to help determine if a person has anorexia, and aid in determining a treatment plan.

A thin woman with long hair is out of focus in the background. In the foreground, a therapist takes notes on paper.

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Professional Screenings

In non-emergency situations, the process of diagnosing anorexia usually begins with an initial overall assessment from a healthcare provider.

During this assessment, the healthcare provider will take the person’s medical and psychiatric history, including their family history, and perform a full physical examination. This examination might include:

  • Asking about diet history, including what foods the person eats, their eating habits, thoughts about food, etc.
  • Questions about body image and weight loss history
  • Height and weight measurements
  • Comparisons with age-based growth charts
  • A discussion of binging and purging behaviors, including the use of laxatives, diet pills, or supplements
  • A review of any medications the person currently takes
  • Questions about menstrual history
  • A discussion about exercise history and practices
  • Asking about a family history of eating and feeding disorders
  • A discussion about substance use and mental health (mood, depression, anxiety, suicidal thoughts), including a family history of substance use disorders or psychiatric disorders
  • Checking vital signs, including heart rate, temperature, and blood pressure
  • Looking at skin and nails
  • Listening to the heart and lungs
  • Feeling the abdomen

A primary healthcare provider may also make a referral to a mental health expert such as a psychiatrist. Eating and feeding disorders often exist alongside other mental health disorders.

DSM-5 Criteria

To meet the criteria for anorexia set out in the Diagnostic and Statistical Manual of Mental Disorders (DSM–5), the following must be met over a period of at least three months:

  • Restriction of energy intake relative to requirements, leading to significantly low body weight in the context of age, sex, developmental trajectory, and physical health (less than minimally normal/expected)
  • Intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain
  • Disturbed by one’s body weight or shape, self-worth influenced by body weight or shape, or persistent lack of recognition of the seriousness of low body weight

In other words, a person:

  • Exhibits behaviors that make it difficult or prevent maintaining an adequate weight for health: These behaviors can include restricting food intake, intense exercise to “counteract” food, self-induced vomiting, or misusing medications such as laxatives, diuretics, insulin, or enemas.
  • Has an intense fear of becoming fat or of weight gain: This fear can persist even when the person has a body weight that is too low for their health. They may exhibit body checking behaviors such as frequently weighing and/or measuring themselves and frequent “mirror checks.” Weight loss or lack of weight gain rarely eases this fear.
  • Perceives their weight and shape inaccurately or in a distorted way: They may see themselves as bigger than they are, have negative feelings about their body, and feel that their weight and shape are the most important part of themselves.
  • Does not fully comprehend or appreciate the seriousness of their condition or behaviors: They may not see the dangerous health impacts of their condition or behaviors, including life-threatening risks of cardiac arrest, suicidality, and other health conditions that can lead to death.

In the past, the criteria for anorexia included the absence of a menstrual cycle. This has been removed as it excluded people who do not menstruate, and it made it difficult to evaluate children and young adolescents.

Anorexia diagnostic tools also focused in the past specifically on weight loss. Because children need to grow in order to maintain their health, the diagnosis of anorexia now includes not gaining weight developmentally appropriately.

Does Anorexia Always Mean Being Underweight?

While the criteria for anorexia specify having a body weight that is too low for health, a person does not need to be underweight to have other eating or feeding disorders.

Labs and Tests

Tests may be performed to rule out other health conditions that could be causing weight loss and other symptoms, or to check for problems that may have arisen as a result of anorexia.

These may include:

Blood Tests

  • Complete blood count (CBC)
  • Checks for levels of albumin (a liver protein)
  • Measure of electrolytes
  • Kidney function tests
  • Liver function tests
  • Measure of total protein
  • Thyroid function tests

Urinalysis

Certain metabolic functions can be measured with a urine test.

Urinalysis also looks at the color and appearance of the urine, its microscopic appearance, and its chemistry.

Other Tests and Procedures

A bone density test may be administered to check for osteoporosis.

An electrocardiogram (ECG) may be ordered to check for problems with the heart such as slow heart rate or abnormal heart rhythm.

X-rays may be taken to check things like stress fractures or broken bones, lung or heart problems.

Self/At-Home Testing

Questionnaires, such as the SCOFF Questionnaire for adults, are typically used for screening for eating disorders during routine health exams and sports physicals, and may be a helpful tool for self-assessment.

The SCOFF Questionnaire for Eating Disorders in Adults

  1. Do you make yourself sick because you feel uncomfortably full?
  2. Do you worry you have lost control over how much you eat?
  3. Have you recently lost more than 14 pounds in a three-month period?
  4. Do you believe yourself to be fat when others say you are too thin?
  5. Would you say that food dominates your life?

One point is given for every “yes” answer. A score of two or higher indicates a likelihood of anorexia nervosa or bulimia nervosa and that the person should see a healthcare provider for further steps.

Emerging Research

A 2018 study indicates that there may be gender differences in the presentation and diagnosis of anorexia and bulimia, specifically as it refers to the severity indicators in the DSM-5. This study also showed that the severity indicators in the DSM-5 for anorexia may not give an accurate measurement for males or females.

A 2017 study supports the need for more research on the accuracy and validity of the severity measures indicated in the DSM-5.

A study done in 2017 suggests that more measures are needed to distinguish between constitutional thinness and anorexia, particularly since the removal of amenorrhea (lack of a menstrual period) from the DSM criteria for anorexia. This study recommends the use of testing for free T3 levels in addition to the existing criteria.

Resources

If you or a loved one is coping with an eating disorder, contact the National Eating Disorders Association (NEDA) Helpline for support at 1-800-931-2237. 

For more mental health resources, see our National Helpline Database.

A Word From Verywell

It can often be difficult for a person who is experiencing anorexia to recognize that they have a health problem. Diagnostic tools such as screening tests, physical and psychological examinations, and other health procedures can help determine if you or someone you love is experiencing disordered eating such as anorexia.

Once the condition has been recognized, there are ways to help, and recovery is possible.

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Article Sources
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