Hello! Welcome to HCM! I carefully read your question and would explain that a careful differential diagnosis should be done to differentiate between different causes that may lead to your symptomatology: - A lung disorder. Respiratory function tests should be done to examine your respiration. Shortness of breath during exertion could be related to a lung disorder. - Myocardial ischemia: I would like to have some more information on the stress tests that you have performed. If you have performed repeated cardiac stress tests which have resulted normal, a cardiac disorder can be excluded. - A backbone disorder: This could be related to shortness of breath during exertion. A cervico-thoracic X ray study would help examine for possible chronic degeneration of spinal column Besides, I would recommend performing some blood lab tests (complete blood count for possible chronic anemia, inflammation tests, fasting glucose for possible hypoglycemia, blood electrolytes), to exclude other metabolic causes, which could exacerbate your clinical situation. Hope to have been helpful! Best wishes, Dr. Iliri