What Causes Headache After Getting Up In Morning?

hey doc,i am 53yrs old lady.every morning i get up,i have headache.now the problem has started more frequently after every 10 days or so and remains till 3-4 days.then i take warm water and divya churan and problem subsides.i feel its acidity or something else...please guide.my weight is 66kg,height is 5 feet.