How is anorexia nervosa diagnosed?
If symptoms are present, the doctor will begin an evaluation by performing a complete medical history and physical examination. Diet history will be taken – the individual will be asked about the quantity and variety of foods/food groups and thoughts about food. The doctor will ask about body image and weight loss history and measure weight and height and compare with age-based weight and growth charts. Binge and purging frequency and elimination habits (diet pills, laxatives, supplements) will be discussed. Current medications will also be reviewed. The doctor will also ask about menstrual history, exercise history and family history of eating disorders, substance abuse and psychological disorders (mood, depression, suicidal thoughts).
Although there are no laboratory tests to specifically diagnose anorexia nervosa, the doctor might use various diagnostic tests, including laboratory values (a blood test), to rule out physical illness as the cause of the weight loss, as well as to evaluate the severity of illness or the effects of the weight loss on the body’s organs. The doctor may order an electrocardiogram (ECG) to check for slow heart rate, chest pain, abnormal heart rhythm, or heart flutter.
To be diagnosed with anorexia nervosa, the doctor will determine if three criteria have been met:
- Does the person weigh less than the minimum that is considered normal for their age, sex, stage of growth and development, and physical health?
- Does the person have an intense fear of gaining weight or becoming fat or display ongoing behavior that interferes with weight gain even though the individual is at a significantly low weight?
- Does the person show a disturbance in the way they view their body weight or shape; does their body weight or shape have a strong influence on their self-image; does the person lack recognition of the seriousness of their current low body weight?