When trying to determine if you have an eating disorder, your doctor will probably ask questions about your weight and eating habits. For example, you may be asked,
if you have lost a lot of weight recently
how you feel about your weight
if you make yourself vomit regularly
(in women and girls) whether your periods have stopped and, if so, for how long
if you think you have an eating problem
It is important to answer these questions honestly. Your doctor is not trying to judge you. They just need to accurately assess your condition in order to help you.
Weight and BMI
Your doctor will usually check your weight. If someone has anorexia nervosa, their weight is generally at least 15% below average for their age, sex and height. Your doctor may also calculate your body mass index (BMI). A healthy BMI for adults is 18.5 to 24.9, although in some cases doctors may be concerned if you have a BMI below 20. Adults with anorexia generally have a BMI below 17.5. The normal BMI for young people depends on their age, so it may need to be plotted on a special chart.
Your doctor may not need to carry out any tests to diagnose anorexia nervosa, but they may check your pulse and blood pressure, take your temperature and examine your hands and feet to see if you have signs of any complications of anorexia.
Your doctor may also ask you to carry out some simple physical exercises, such as moving between sitting, squatting and standing, to assess your muscle strength.
If you have anorexia, you have a higher risk of developing some heart conditions, such as an irregular heartbeat (arrhythmia). Sometimes an ECG (electrocardiogram) may be needed. This is where a number of electrodes (small, sticky patches) are put on your arms, legs and chest to record the electrical signals produced by your heart.
Your doctor may also perform blood tests to check your general health and the levels of chemicals or minerals such as potassium.