What causes shortness of breath and fatigue after an open heart surgery?
Patient: Hi. My father had open heart surgery in March. Up until then, he also had shortness of breath, low oxygen, and fatigue. For a month or so after the surgery, he felt better, but is now experiencing the same symptoms he had before the surgery. He had a nuclear stress test which showed no blockages and a CT scan of his lungs which showed nothing either. He has type 2 diabetes. Years ago he took medication for an under-active thyroid. Doctor: Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.  Shortness of breath, fatigue, may be due to cardiac illness, pulmonary disease, allergic conditions, anemia, infection, all these needs differentiation, beside these shortness of breath and fatigue may be functional in origin, condition demands the clinical examination and some basic tests like routine hemogram, EKG, ECHO.  Hope I have answered your query, Let me know for further assistance.