Headache is pain in any region of the head. Headaches may occur on one or both sides of the head, be isolated to a certain location, radiate across the head from one point, or have a viselike quality. A headache may appear as a sharp pain, a throbbing sensation or a dull ache. There are several hundred different types of headaches, but the four very common types are: sinus, tension, migraine, and cluster. The trigger of headaches might also include food.