I have a friend that have a headache come-up unexpectedly.
But after a time the pain lesser untel its gone.
I notice even her headache is gone, later or the next day her headache will come back.
I told her to go to a Dr. for just a check-up, but she don't what to.
I what to know what would be the cure of her headache.
Thanks for your time:)

Really depends on what is triggering them.
Remove the trigger and the likelihood of the headaches returning is lessened.

Triggers can include over use of a computer display, other eye strain, stress and various environmental factors.

Oh! OK...
Even she don't do anything we are just like setting or talking. She just unexpectedly complain about her head hurts.