Examine your sleep habits... I suffered sleep deprevation for most of my freshman and sophomore years in college... due to the fact that I was taking 19 hours of mechanical engineering classes and had 3 baseball practices a day... one in which was at 5:30 in the morning.... So examine your sleep habits... you should get more than 8 hours of sleep every night. When I suffered sleep deprevation I was only getting between 2 and 3 hours of sleep a night... after about a month of it my body shut down. It started with a terrible headache... then I was so weak I just wanted to stay in bed... then I had a fever... I slept for almost 15 hours straight... then slept for about 15 more... After that I felt much better... I still get rundown like that every two months or so.... that's one thing to look at.

Also monitor your caffeine intake. Almost 75% of Americans suffer from some level of caffeine addiction... Headaches are a main symptom of caffeine withdrawl. Many people take medicines to remedy the migraine like Excedrin when all they really need is a cup of coffee... Hence the reason why the makers of Excedrin put caffeine in the actual ingredients of the medication... So that's something else to look at.