A doctor will evaluate a patient’s body mass index (BMI). The BMI is a measurement of body fat. It is derived by multiplying a person's weight in pounds by 703 and then dividing it twice by the height in inches. (BMI calculators are available online.)
- A healthy BMI for women over age 20 is 19 - 25.
- Those over 25 are considered overweight; those over 30 are considered obese.
- Those under 17.5 are considered to be at risk for health problems related to anorexia. (However, young teenagers can have lower BMIs without necessarily being anorexic.)
For example, a woman who is 5'5" and weighs 125 pounds has a healthy BMI of 21. A woman at the same height who weighs 90 pounds would have a dangerously low BMI of 15.
Diagnosing Bulimia Nervosa
A doctor generally makes a diagnosis of bulimia if there are at least two bulimic episodes per week for 3 months. Because people with bulimia tend to have complications with their teeth and gums, dentists can play a crucial role in identifying and diagnosing bulimia.
Diagnosing Anorexia Nervosa
Generally, an observation of physical symptoms and a personal history will confirm the diagnosis of anorexia. The standard criteria for diagnosing anorexia nervosa are:
- The patient's refusal to maintain a body weight normal for age and height
- Intense fear of becoming fat even though underweight
- A distorted self-image that results in diminished self-confidence
- Denial of the seriousness of emaciation and starvation
- The loss of menstrual function for at least 3 months
The doctor then categorizes the anorexia further:
- Restricting (severe dieting only)
- Anorexia bulimia (binge-purge behavior)
Diagnosing Complications of Eating Disorders
Once a diagnosis is made, a doctor will check for any serious complications of starvation and also rule out other medical disorders that might be causing the anorexia. Tests should include:
- A complete blood count
- Tests for electrolyte imbalances
- Test for protein levels
- An electrocardiogram and a chest x-ray
- Tests for liver, kidney, and thyroid problems
- A bone density test
Previous Section
Review Date: 02/18/2011
Reviewed By: David B. Merrill, MD, Assistant Clinical Professor of Psychiatry,
Department of Psychiatry, Columbia University Medical Center, New
York, NY. Also reviewed by Harvey Simon, MD, Editor-in-Chief,
Associate Professor of Medicine, Harvard Medical School; Physician,
Massachusetts General Hospital; and David Zieve, MD, MHA, Medical
Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
