Hello! Thank you for your question on HCM! Regarding your concern I would say that there are different types of headaches which are triggered by a straining physical activity. It may be a benign type of headache like a primary stabbing headache, which is temporary. But it may also be a sign of an intracranial aneurysm which is leaking small amounts of blood (sentinel headache) or a brain tumor. But a brain tumor would be less probable as the headache would repeat in a progressive pattern. I would recommend you to consult with your GP and have a physical examination and a routine blood analysis. If the headache repeats a brain CT scan followed by an angiography may be necessary to exclude the above mentioned possible causes. Hope to have been of help! Greetings! Dr. Aida