Had a headache for over 5 days now, what could it be?

If I was you, I would call a local nurse hotline, or seek professional medical assistance.

If you can identify any of these as the source, try eliminating it. A lot of people get them from too much sugar, not enough sleep, etc.

http://shine.yahoo.com/healthy-living/top-ten-reas...

DEHYDRATION

PAIN MEDICATIONS

CAFFEINE

STRESS

SINUSES

BLOOD SUGAR IMBALANC

CERTAIN FOODS

WEATHER OR CHANGE IN ALTITUDEHORMONES

EXPOSURE TO SECOND-HAND SMOKE

Have you ever had a headache before that has not gone away in a reasonable amount of time? If you have, or if this is brand new I would counsel you to see a doctor. The symptoms you describe could be a tension headache or possibly a migraine, especially with the nausea component. I have had migraine headaches for most of my life and they are most debilitating. You cannot be sure unless a doctor sees you and makes a proper diagnosis. There are currently some medications that can be taken for migraine but they are all prescription so you definitely need to see a doctor and then maybe a referral to a neurologist for further evaluation. Good luck to yu and you have my sympathies.

Go see a doctor could be sinus trouble.