Any persistent headache like this that does not get better after a few days really needs to be evaluated by your primary care doctor
as soon as possible.
There are several different causes of headache that is persistent. A few of these are rare but also very serious, such as a brain tumor. The first thing your doctor will do is perform a thorough neurological exam to make sure you do not have any evidence of these serious causes. If there is any concern after the neurological exam, they will probably want to get an MRI
of the brain to rule things out.
Assuming that your neurological exam is normal, then the two most common causes of persistent headache are tension headache and migraine
headache. These two types of headache typically have different patterns, which can usually be teased out by your doctor. It is important to make the distinction, because the two types of headache are generally treated quite differently. For example, tension headaches often respond to changes in lifestyle (sleeping better, exercising more) and painkillers. Migraine headaches, on the other hand, may require a daily medication to reduce the frequency and severity of the headache attacks or specialized medications to 'break' the headache.
Make an appointment with your doctor today. I hope you’re feeling better soon!