Hello! Thank you for asking on HCM! Regarding your concern, I would like to explain that many disorder could cause this clinical scenario. I would recommend consulting with your GP for a careful physical examination, a resting ECG, a chest x ray and some blood lab tests : - complete blood count for chronic anemia - kidney and liver function tests - blood electrolytes ( including calcium and magnesium) - thyroid hormone levels and cortisol plasma levels ( to exclude possible thyroid and adrenal gland dysfunction) -fasting glucose and glucose tolerance test ( diabetes could cause chronic fatigue and thirst) - a cardiac ultrasound to examine your cardiac function. -inflammation tests (fibrinogen, PCR, sedimentation), because an autoimmune disorder could mimic such a clinical scenario. -blood and urine osmolarity ( this test helps define the cause of your thirst) I also advise monitoring your blood pressure in both sitting and standing up position. A head up tilt test is necessary to exclude possible orthostatic hypotension. Hope to have been of help! Best wishes, Dr. Iliri