Hello! Thank you for asking on HCM! I understand your concern, and would like to explain that a careful differential diagnosis of different causes related to this symptomatology (such as low blood pressure, orthostatic hypotension, chronic anemia, an infection). Even anxiety could mimic this clinical scenario. I would like to know the type of surgery you have gone through. Was it a small intervention? Did you need blood transfusion during the intervention? Had you had any fever in the days after the intervention? I recommend consulting with your attending physician for a careful physical examination, a resting ECG and some blood lab tests: - complete blood count (anemia and infection) - PCR, sedimentation rate - kidney and liver function tests - thyroid hormone levels (thyroid gland function) - cortisol plasma levels (adrenal gland function) - blood electrolytes, etc. You should closely monitor your blood pressure in sitting and standing up position. A decrease more than 20mm Hg on your systolic blood pressure while standing up, compared with sitting position, may indicate orthostatic hypotension. A head up tilt test is needed to rule in/out this possible diagnosis. If all the above tests result normal, the most probable cause of your symptoms would be anxiety. In such a case, you should consult with a specialist of the field. Hope to have been helpful! Best wishes, Dr. Iliri