Physicians may diagnose anorexia nervosa based on the patient’s symptoms and eating habits. During an initial consultation, a physician will record the patient’s weight and perform a thorough physical examination including:

• Checking vital signs, such as heart rate and blood pressure
  
  
• Evaluation of patient’s skin, abdomen and teeth
  
  
• Neurological examination to evaluate other potential causes of weight loss and/or vomiting, such as liver disease or a brain tumor

A physician will also compile a comprehensive medical history including any family history of physical and mental disorders (e.g., depression, obsessive-compulsive disorder) as well as inquire into the patient’s history of dieting and/or eating patterns. Some of the questions a physician may ask include:

• Has the patient recently lost more than 14 pounds (6.35 kg) in a three-month period?
  
  
• Does the patient believe they are fat when others say they are too thin?
  
  
• Does food dominate the patient’s life?
  
  
• Does the patient induce sickness (vomiting) because they fear gaining weight?
  
  
• Does weight affect the patient’s self-image?

In addition, a physician may order diagnostic tests to identify any signs of complications of anorexia nervosa including malnutrition, anemia (reduced red blood cell count), reduced heart rhythms (bradycardia), digestive problems (e.g., constipation), bone density loss or changes in the menstrual cycle.

Additional diagnostic tests may include:

• Blood tests. Laboratory analyses – including a complete blood count (CBC) – of blood samples to measure levels of hormones, enzymes, proteins, electrolytes, vitamins and other substances to assess the function of various organ systems including the liver, kidney, thyroid and pituitary glands as well as the ovaries (female reproductive glands).
  
  
• Urinalysis. Chemical examination of a urine sample to screen for urinary tract infection, kidney disease and diseases of other organs that result in the appearance of abnormal metabolites (break-down products) in the urine.
  
  
• Electrocardiogram (EKG). This test measures the pattern of electrical impulses generated by the heart. During the procedure, electrodes (devices that detect electrical impulses) are attached to the patient’s chest. The electrical impulses are then recorded on a graph. In patients with anorexia nervosa, an EKG can help detect irregular heartbeats (e.g., bradycardia) and identify the presence of any damage to the heart.
  
  
• Imaging tests (e.g., x-ray, MRI, CAT scan). These tests are useful in detecting the presence of any damage in the chest, digestive tract, organs and/or brain caused by anorexia nervosa. For example, a chest x-ray may reveal whether anorexia nervosa has damaged the heart muscles by reducing the size of the heart.
  
  
• Bone density test. During this test, a physician may use a device called a sonometer to pass painless sound waves through the bones to measure the density of the bones and check for signs of bone mass loss (osteoporosis).