A headache or cephalalgia refers to pain anywhere in the different areas of the head or neck. This includes the nine pain-sensitive structures, which include the cranium (the periosteum of the skull), muscles, nerves, arteries and veins, subcutaneous tissues, eyes, ears, sinus and mucous membranes.
A chronic daily headache (CDH) is commonly defined as a headache occurring for 15 or more days in a month or at least for three months. Chronic daily headache (CDH) is where a person experiences frequent headaches that are challenging to manage. A recent population-based survey shows that nearly 5% of the unselected population has daily headaches. Most of the patients with persistent headaches have a primary headache syndrome. Headache is the most common complaint which brings a patient to a neurologist. Although most headaches are benign in origin, some can have severe and sometimes life-threatening causes.