Hello! Thank you for asking on HCM! Your symptoms may be related to dehydration or a metabolic disorder. I recommend consulting with the GP for a careful physical examination, a resting ECG and perform some lab test like: - complete blood count for chronic anemia - thyroid hormone levels (to exclude possible low thyroid function) - blood sugar -blood electrolytes ( including magnesium and calcium) -kidney and liver function tests -plasma levels of cortisol (low cortisol levels may cause a similar clinical scenario. A head up tilt test may be necessary to rule out/in orthostatic hypotension, which could mimic a similar clinical scenario. I would also recommend performing a cardiac ultrasound to examine better the cardiac function as a possible cause of low blood pressure and chronic fatigue. Meanwhile I recommend taking plenty of water to avoid dehydration. Hope to have been helpful! Best wishes! Dr. Iliri