The diagnostic process may depend on the type of eating disorder a person has. However, it will typically involve physical and physiological evaluations, including body mass index (BMI) measurements and blood tests.

Eating disorders are complex and potentially life threatening conditions that cause a persistent disturbance in a person’s eating behaviors.

An eating disorder diagnosis is critical in helping affected people receive the appropriate treatment and support to regain their physical and mental health.

This article explains how doctors diagnose eating disorders, including physical and physiological evaluations, diagnostic criteria, available treatment options, and strategies for coping with these disorders.

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When diagnosing an eating disorder, doctors may start by looking at a person’s medical history. After this, they will carry out a physical evaluation.

During this process, healthcare professionals, such as physicians or psychiatrists, will assess a person’s physical health. This assessment may include the following areas:

Weight and BMI

Individuals with eating disorders may exhibit significant fluctuations in weight, which can be an important indicator of the disorder.

Doctors calculate a person’s BMI based on their weight and height. BMI is a screening method that can categorize someone into the following weight statuses:

  • underweight
  • healthy weight
  • overweight
  • obesity

A BMI below 18.5 suggests that someone is underweight. A very low BMI may occur if someone has anorexia nervosa.

Although eating disorders may cause a preoccupation with weight, not all eating disorders cause people to be underweight. People with eating disorders may also fall in the BMI categories of a healthy weight range, overweight, or obesity.

BMI is a simple screening tool that cannot diagnose a person’s health. A doctor requires further diagnostic tests to determine if a person has an eating disorder.

Learn more about BMI calculators and charts.

Vital signs

Monitoring vital signs, such as heart rate, blood pressure, and body temperature, can help identify potential complications of eating disorders.

For example, bradycardia, an abnormally slow heart rate, and hypotension, low blood pressure, are common in individuals with anorexia nervosa.

Physical symptoms

A doctor may ask about symptoms and look for physical symptoms during their initial evaluation. Symptoms of an eating disorder may include the following:

Gastrointestinal issues

Individuals with eating disorders may experience gastrointestinal problems, such as:

A doctor may also conduct a physiological exam to assess a person’s overall health, which an eating disorder can negatively impact. This evaluation may include blood tests to check for:

Electrolyte imbalances, particularly low potassium levels, can pose severe risks, including an irregular heartbeat, which is a common complication in eating disorders.

Different eating disorders have distinct diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR). For example, to diagnose bulimia nervosa, a doctor must observe the following:

  • recurrent episodes of compulsive eating, consuming large amounts of food in a short time
  • compensatory behaviors to prevent weight gain, such as self-induced vomiting, laxative use, excessive exercise, or fasting
  • binge eating and compensatory behaviors occurring at least once a week for 3 months
  • an excessive focus on body shape and weight

As each eating disorder is different, diagnostic criteria help doctors determine the type a person has, which is essential for developing a treatment plan.

If someone suspects they or someone they know has an eating disorder, they should seek medical help. Without treatment, eating disorders can have severe health consequences. Early intervention typically leads to better outcomes.

People can take the following steps if they suspect they have an eating disorder:

  • Find a healthcare professional: This could be a primary care physician, psychiatrist, or registered dietitian with experience treating eating disorders.
  • Share their concerns: Openly share concerns or observations about eating habits, physical symptoms, and emotional well-being. Providing more information may help the doctor assess the situation as effectively as possible.
  • Collaborate on a treatment plan: If a doctor diagnoses someone with an eating disorder, they can work together with the individual to develop a tailored treatment plan.

The specific approach to treatment will depend on the type and severity of the disorder. Treatment for eating disorders can involve medical, nutritional, and psychological components, including:

Coping with an eating disorder can be challenging, both for the affected person and the people around them. The following strategies may help people manage and support recovery:

  • Education and awareness: Learn as much as possible about the disorder to understand the challenges and complexities it causes.
  • Support: Family members and friends can offer emotional support and encouragement to people in treatment. Avoid bringing up their appearance or eating habits, which may be triggering.
  • Self-care: Encourage self-care, such as getting enough rest, managing stress, and engaging in activities that bring joy and relaxation.
  • Staying connected: Stay connected with a doctor and attend therapy sessions or support groups if a healthcare team recommends them.
  • Patience and persistence: Recovery from an eating disorder is a journey that takes time and effort. Celebrate small victories and stay patient and persistent in the process.

Support groups and helplines

People with eating disorders may also benefit from support groups and helplines, such as:

To diagnose an eating disorder, doctors may assess a person’s physical and physiological health, following specific diagnostic guidelines.

The signs of an eating disorder may vary depending on the type of disorder a person has, as well as their circumstances.

Early intervention and ongoing support are key to helping people overcome these complex and potentially life threatening conditions and promoting physical and mental well-being.