Headaches are a common phenomenon that most people have experienced at some point during their lives.  While some people get headaches rarely and relate them to dehydration or pressure changes, others experience headaches on a somewhat frequent basis.

There are numerous types of headaches listed by the international headache society, with an equally large number of causes.  Three of the more common types of headaches are: tension-type, cervicogenic, and migrane.

A tension-type headache tends to feel like a band of tightness or squeezing around the head, and is often described as though the head is being compressed in a vice.  It originates from tension or trigger points in the muscles of the neck and shoulders, often caused by stress, lack of sleep, or poor posture.

A cervicogenic headache occurs when joints of the spine in the neck and base of the skull are not moving properly, and the nerves in the area refer pain to the temples, eyes, and/or forehead.  These headaches are often aggravated by certain neck positions or by repetitive neck or shoulder movements.  They often occur as a result of neck trauma, such as whiplash, but can also be the result of poor posture.

Migrane headaches tend to be more extreme in nature.  They may or may not start with an aura, which involves a visual disturbance up to an hour before the migrane begins.  Migranes can often cause a hypersensitivity to light and sound.  There are several different theories as to what causes these headaches, ranging from constriction and dilation of blood vessels in the head and neck, to mild hypersensitivity reactions caused by specific triggers.

The literature has shown a causal relationship between neck dysfunction and certain types of headaches. This has lead to studies showing the effectiveness of chiropractic care on such headaches.