Hello! Thank you for asking on HCM! I read your question carefully and understand your concern. Your symptoms may be related to low blood pressure or low blood sugar. You should know that after physical exercise, the levels of blood sugar can decrease, mimicking this clinical scenario. A low blood pressure from dehydration or chronic anemia could also be related to this. A metabolic disorder (thyroid dysfunction, adrenal gland dysfunction) can not be excluded too. So, I recommend you to closely monitor your blood pressure different times during the day (in sitting and standing up position). A complete check up by your GP, including : -resting ECG -chest x ray study -head up tilt test for orthostatic hypotension -lab blood tests (complete blood count, fasting glucose, PCR, sedimentation rate, kidney and liver function tests, blood electrolytes, thyroid hormone levels, cortisol plasma levels, etc), are necessary to rule in/out the above mentioned disorders. You should discuss with your doctor on the above mentioned issues. Hope to have been helpful! Best wishes, Dr. Iliri