Headaches may be caused by a number of conditions, such as disorders of the neck, eyes, brain, jaw, or teeth. Headaches with an underlying medical condition are classified as secondary headaches because they are related to the condition. An example of this would be a headache due to neck injury or sinus infection.
The majority of headaches experienced by children and adolescents are not due to serious underlying problems. Both physical and emotional factors must be considered when evaluating headaches.
Headaches classified as primary indicate that the headache itself is the main medical problem, although underlying non-medical causes, such as muscle tension or foods, may be identified. Other contributing factors may include medications, dehydration, or changing levels of hormones. These factors that influence headaches are sometimes called headache triggers.