If you generally consider yourself a healthy person, getting the occasional headache is just one of life's annoyances — an ailment as common (and as seemingly harmless) as the common cold, indigestion, or a mosquito bite. Except... when it's not.
If you've ever had a headache that won't go away with the help of over the counter medicine like acetaminophen or ibuprofen, it may not be a headache at all. It could, in fact, be a migraine. What's the real difference between the two?