Could be allergies, sinus problems maybe even a sinus infection, could be high blood pressure, stress, there are many other reasons. Taking pain medication will only relieve or mask the problem, but you need to know what is the root of the problem, and the only way you can find out is through a medical doctor. You need to check into this right away, because it may be more serious than what you think.
I had headaches all the time and I would take medicine but nothing helped. So my dad said to get my eyes checked because he had the same problem. The cause of my headaches were that I needed glasses like my dad. And I also had an astigmatism in my right eye. Go see your doctor, mate. Hope all turns out alright :)
do you wake up with them or do they progress as the day goes on? age? male or female? yes, the answers matter as there are many triggers which affect men and women differently. food triggers are the most common. let me know if its morning or after and I'll help you work from there.