A "headache" is defined as pain or aching in the head, face, mouth, or neck. Headaches can occur for several reasons and can vary in the location of the pain, how often the pain occurs, and the length of time the pain lasts. Based on this and other information, your healthcare provider can classify what type of headache you have (such as a primary or secondary headache).
A primary headache occurs without an underlying condition; the most common types of these headaches are migraines, tension headaches, and cluster headaches. Secondary headaches are due to an underlying cause, which your healthcare provider can determine based on certain information and testing.