If your doctor suspects that you have anorexia nervosa, he or she will typically run several tests and exams to help pinpoint a diagnosis, rule out medical causes for the weight loss, and check for any related complications.
These exams and tests generally include:
- Physical exam. This may include measuring your height and weight; checking your vital signs, such as heart rate, blood pressure and temperature; checking your skin and nails for problems; listening to your heart and lungs; and examining your abdomen.
- Lab tests. These may include a complete blood count (CBC) and more specialized blood tests to check electrolytes and protein as well as functioning of your liver, kidney and thyroid. A urinalysis also may be done.
- Psychological evaluation. A doctor or mental health provider will likely ask about your thoughts, feelings and eating habits. You may also be asked to complete psychological self-assessment questionnaires.
- Other studies. X-rays may be taken to check your bone density, check for stress fractures or broken bones, or check for pneumonia or heart problems. Electrocardiograms may be done to look for heart irregularities. Testing may also be done to determine how much energy your body uses, which can help in planning nutritional requirements.
Diagnostic criteria for anorexia
The Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association, is used by mental health providers to diagnose mental conditions and by insurance companies to reimburse for treatment.
DSM-5 diagnostic criteria for anorexia include:
- Restricting food intake — eating less than needed to maintain a body weight that's at or above the minimum normal weight for your age and height
- Fear of gaining weight — intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain, such as vomiting or using laxatives, even though you're underweight
- Problems with body image — denying the seriousness of having a low body weight, connecting your weight to your self-worth, or having a distorted image of your appearance or shape