“What could be the possible causes for frequent headaches?”

Headaches can be caused by so many things. It could be Stress, elevated blood pressure, emotional, decreased oxygen, sleep apnea if you’re waking up with headaches, imbalanced, electrolytes, tension headaches, I would start with getting a complete lab work up with your PCP and then follow up for the lab review. Then move on from there to narrow down the Cause