I have had a headache that is at the tip of my for head and goes back over the top of my head for 4 days now what could be causing this?

Muscle tension: The forehead and the areas around the hairline have muscles that contract when we frown or raise our eyebrows. If these muscles are tensed up from stress, they can cause headaches. Worrying about the headache will cause the muscles tense up even more. A muscle tension headache is unpleasant but not serious. But, if your headache is severe and associated with other symptoms, see a doctor.