While typically thought of as "bone doctors", chiropractors actually focus on the nervous system and painlessly, manually adjust the vertebral column in order to affect the nervous system.

According to Gray's Anatomy, the nervous system is the master system in the body and controls and coordinates all other systems such as respiratory, digestive, muscular, and immune. The nervous system includes the brain, spinal cord, the spinal nerves that exit the vertebral column through openings on the sides of each vertebra, and all the peripheral nerves that branch off to serve organs, tissues, blood vessels, muscles, etc. Information from the environment, both external and internal, goes through the spine to get to the brain. In the same manner, information and decisions made in the brain go through the spine to affect certain outcomes. It is a two-way flow of information.

The intention of the chiropractic adjustment is to remove any disruptions or distortions of this energy flow that may be caused by slight vertebral misalignments that we call subluxations. Chiropractors are trained to locate these subluxations and then to remove them, thereby restoring the normal flow of nerve energy in terms of both quality and quantity. The idea is that if the master system, which is the nervous system, is healthy and functioning well, then the other systems under its control will also function in a more optimal fashion.

Chiropractic is based on the belief that the same innate intelligence that can grow a single cell into a complex human being, made of billions of cells, can also heal the body if it is free of disturbance to the nervous system. For example, if the area of spine that supplies nerve flow to the lower leg is subluxated (or disturbed) then information going to the brain regarding that organ and its function, will be distorted and the brain will not be receiving accurate data, so the patient will experience a shooting pain down the leg, known as sciatica. Likewise, decisions made in the brain and conveyed along the nervous pathways will be disrupted and the correct responses will be unable to be made and the patient may also experience a numbing sensation in certain areas of the leg. It is essentially the same scenario for all other organs, muscles, blood vessels and so forth. When a chiropractor removes this interference, then the nervous system functions more optimally and the body is able to heal itself via the two-way communication system.