<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi my situation is this : I have a 13 year old active, fit young girl who within the last year has been experiencing stomach chest pains. It was really bad the other day hurt her to breath in out. Upper back pain as well. I took her to ER where they did several tests one being a blood test whicChatDoctore back as a high reading of 660 for her D-Dimer. Do I need top worry ? They would like to repeat this test. Is she at risk for a heart attack ?  <response>: Hello, High D dimer with chest pain and breathlessness is more suggestive of pulmonary embolism PE. But PE is unlikely in a 13-year-old young girl. So better to get done repeat D dimer test. If it is normal then no need to worry about PE or other heart diseases. But if it is high, then she will need CT pulmonary angiography. Hope I have answered your query. Let me know if I can assist you further. 