What Cases Headache In Morning After Sleep?

I wake up in the morning after sleeping usually 8 hours still tired and with a headache. I find myself forgetful and easily lose my temper the last few months. Is it my age--48? Usually do not take too much pain meds because worried that I will have rebound headaches. No nasal congetion but often feel sinus pressure. Pretty much always have some degree of the headache. Tired and sore muscles.