The exact cause of headaches is not completely understood. It is thought that many headaches are the result of tight muscles and dilated, or expanded, blood vessels in the head. Other headaches may be caused by an alteration in the communication between parts of the nervous system that relay information about pain, coming from the area of the head, face, and neck. Occasionally, there is an actual problem in the brain, such as a tumor or malformation of the brain, although this is rare.
The way a child exhibits a headache may be related to many factors, such as genetics, hormones, stress, diet, medications and dehydration. Recurrent headaches of any type can cause school problems, behavioral problems and/or depression.