Hi, Purging and starving yourself can have serious consequences on your body, and the symptoms you described could be a result of your eating disorder. The headache and burning sensation in your stomach could be a sign of acid reflux, which occurs when stomach acid flows back into the esophagus. This can be caused by the stomach being empty for a long period of time or by consuming acidic foods or beverages. The sharp, dull pain in your abdomen could be a sign of an ulcer, which can be caused by the same factors. The tremors and shaking could be a sign of hypoglycemia, which occurs when your blood sugar levels drop too low. This can be caused when not enough carbohydrates or calories are a part of the diet. The fast heartbeat and sharp pains in your collarbone area could be a sign of a panic attack, which can be triggered by stress and anxiety. It s important to seek medical attention for these symptoms, as they could have serious consequences on your health. I would also recommend seeking help for your eating disorder, as it can be a dangerous and potentially life-threatening condition. There are resources available to help you overcome this disorder, such as therapy and support groups. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. H. Kay, General & Family Physician