<s>[INST] i started two weeks ago with dull heartaches. The pain left but then pressure in my head started. Severe fatigue and felt like I was in a fog. I have seen my Dr and had a CT scan which was clear. Thought I was improving, however pressure and fatigue is back. I m very active 53 yr old yoga instructor. Help [/INST] Hello, check your blood is it in normal, most common reason would be fluctuations in it.  Considering you have to a doctor, so he must have checked it.  So now the arena is wide.  During to simple deficiency of vitamin b12 or vitamin D, correct the same Anemia of your hemoglobin is on lower side Cardiac, best to rule out is a stress testable the season, if it's hot, do keep adequate HY Chat Doctor.  A more detailed history and cross questioning would help us resolve your query in a better perspective.  Regards  </s>