Why You Wake Up With A Headache
You’re coming off a stimulant
If you drink a lot of coffee throughout the day, or you take certain medicines that contain a stimulant like Excedrin or Claritin, you could wake up with a headache. This occurs because, during the night, the stimulant wears off, causing the blood vessels in your brain to constrict. You only notice the resulting pain once you wake up.