Hello! Thank you for asking on HCM! As your aunt is suffering form congestive heart failure, medical therapy should include for sure diuretics, to relieve her symptoms like dyspnea and control congestion. Spironolacton has been shown beneficial for HF treatment due to its antialdosteronic effects, and helping to maintain the potassium equilibrium during loop diuretics use. Heart and kidney are closely interrelated, that is if one of them fails to work properly, it will be for sure important implications on the other s performance. So, when treating HF a special attention should be paid to the kidneys (as their function are a marker of treatment effectiveness and a prognostic indicator too). Regarding pain during urination, I would like to assure you that it is not caused by spironolacton intake. Your aunt needs t oconsult wit hher attending doctor, as probably an urinary infection or other urologic involvements may be present (indipendent of HF treatment). Some additional tests may be necessary (abdominal ultrasound, total urine tests, etc). Hope to have been helpful! Greetings! Dr. Iliri