Headaches are one of the most common medical complaints, and are characterized by dull, aching or throbbing pain which can be centered in the temples or other areas in and around the cranium. There are many causes of headaches, including insufficient sleep, dehydration, stress, anxiety and exposure to loud noises. In some cases, no root cause may be identified; recurrent headaches may be a symptom of a more serious medical condition. Migraines are specific types of headaches, which are typically severe, self-limited and recurrent. They are rooted in the autonomic nervous system and typically require specially prescribed medications to control; most migraines do not fully respond to standard headache treatments, which normally center around over-the-counter pain relievers, rest and/or cool compresses applied to the affected region.