Hello! Welcome and thank you for asking on HCM! I understand your concern and would explain that his cough could be related to different possible causes: - heart failure. Does this cough worsen in lying down position? A cardiac ultrasound would help evaluate his cardiac function. In such case optimization of his actual therapy may be needed. - some medications can cause chronic cough. What is his actual therapy? Is he taking any ACE inhibitors? - a lung disorder. A chest X ray and respiratory tests are needed too. - an allergic reaction. If all the above mentioned causes are excluded some allergy tests may be needed. You should discuss with his doctor on the above issues. Hope you will find this answer helpful! Best wishes, Dr. Iliri