Hello! Thank you for your question on HCM! I appreciate your concern! There are different causes of headache during the night. It may be just a sinus infection, or a sleep headache ( hypnic headache), but it can also be caused by a tumor or any other lesion of the brain, which raises the intracranial pressure. I recommend you to consult with your GP, have a careful physical examination, a blood analysis for infection. A brain CT scan may be necessary to exclude possible brain lesions. Hope to have been of help! Greetings! Dr. Aida