<s>[INST] I am 46 year old female, have been having shortness of breath, difficulty breathing and my left elbow was hurting a little bit. Went to hospital, blood work, chest x-ray and ekg were done, nothing showed up but an elevated d-dimer (1.0). The doctor ordered a cat scan with dye to rule out a clot/tumor, showed nothing. I have not been feeling well at all. What could this be? [/INST] Thanks for your question on Chat Doctor. I can understand your situation and problem. I think you should consult pulmonologist and get done 1. PUT (pulmonary function test)2. CT pulmonary angiography. Bronchitis can cause breathlessness. So PFT is needed to rule out bronchitis. D dimer is high in your case. So possibility of Pulmonary embolism is there. So pulmonary angiography is needed to rule out embolism. Consult pulmonologist and discuss all these. </s>